For those actually interested in the legal distinction between Consent while intoxicated, and DUIs, here's the legal answer from a Canadian Law Perspective.

Please note! I am not taking sides here. I am not saying whether the law is right, or needs changing. I am simply reporting what the law is, and the rationale behind it.

CONSENT

At law, consent cannot be given if a person lacks the requisite mental capacity to give consent. This applies in contracts, in consent to medical procedures, and in sexual contact.

Note that consent is different than the law of duress, which stands for the proposition that a person is not responsible for their actions if they are under the compulsion or threat of force. The two bodies of law are distinct, but function in mostly the same way, and overlap in some cases.

Mental capacity is central to the issue of consent. If a person is not able to reasonably contemplate the nature of an action, or its consequences, then the law does not permit them to consent to that action. A few examples of situations where mental capacity can be compromised are: (1) minor children, (2) mental handicap, (3) impairment by intoxication.

Minor children are too young to understand what they are doing. That is why a 5 year old cannot sign a binding contract. If I get a 5 year old to sign a binding contract that says "if I give you a mars bar today, you will give me $1,000 when you turn 18", a court will not enforce that contract because the child lacks the capacity to enter into that contract. Similarly, a young child is incapable of consenting to sexual activity until they reach the Age of Consent. No one is arguing that young children are incapable of giving consent.

Adults who suffer from cognitive impairment are also incapable of providing meaningful consent. Whether the defect came from birth (eg. Downs Syndrome), injury (eg. brain damage), or disease (eg. Alzheimer's), adults lacking the requisite mental capacity cannot enter into contracts, consent to medical treatment, or engage in sexual activity. I am from the Province of Alberta, where there is an entire government agency responsible for this. If an adult is incapable of making decisions for themselves, then another person (typically a family member) can step up and make decisions for them provided they are granted guardianship or trusteeship over the adult.

The third example is impairment by intoxication or drug use. If I am very drunk, or high, and cannot understand what I am doing, then I can't sign a binding a contract or consent to a medical procedure. If I walked into an army recruitment centre stumbling over chairs, they would not let me enlist, because I lack the ability to enter into that commitment. Even if I am very "gung ho" about it, I still cannot meaningfully consent to it. And this rule applies equally to men and women. The same applies to sexual acts - at least as far as the law is concerned.

Under the Criminal Code of Canada, assault is defined by section 265:

Assault

  1. (1) A person commits an assault when (a) without the consent of another person, he applies force intentionally to that other person, directly or indirectly;

Notice that there are two requirements for assault. (1) A lack of consent; and (2) An intentional application of force (any touching is considered an application of force).

The Criminal Code also explains where consent is not present.

Meaning of “consent”

273.1 (1) Subject to subsection (2) and subsection 265(3), “consent” means, for the purposes of sections 271, 272 and 273, the voluntary agreement of the complainant to engage in the sexual activity in question.

(2) No consent is obtained, for the purposes of sections 271, 272 and 273, where (a) the agreement is expressed by the words or conduct of a person other than the complainant; (b) the complainant is incapable of consenting to the activity; (c) the accused induces the complainant to engage in the activity by abusing a position of trust, power or authority; (d) the complainant expresses, by words or conduct, a lack of agreement to engage in the activity; or (e) the complainant, having consented to engage in sexual activity, expresses, by words or conduct, a lack of agreement to continue to engage in the activity.

For intoxication, we look to subsection (b). We have already discussed areas where the law deems a person to be incapable of having consent, and all of them apply equally to this section. Notice that nowhere do these sections differentiate between men and women.

Sexual Assault = sexual contact - consent. Consent goes away if someone is incapable of giving consent. Serious intoxication vitiates consent. This applies to men and women equally (formally under the law anyway, judges may still apply the law inconsistently between the sexes, but that is a different issue).

Intoxication as a Defence to Criminal Acts

In Criminal law, two things are required to find a person guilty of an offense. (1) The court must show that the accused has committed the Actus Reus of the offence (i.e. the court has to find that they actually did the illegal thing). (2) The court must also show that the accused had the requisite Mens Rea (i.e. that in addition to committing a guilty act, they also had the requisite mental capacity to understand the nature of the act they committed). Mens Rea is the dimension where arguments like Temporary Insanity come from. If a person lacks the mental capacity to understand the nature of their own actions, then we cannot them accountable. So if a 5 year old accidentally shoots someone, while they have caused a persons death, we do not put them in jail because they did not understand what they were doing. Similarly, if a person sleepwalking pushes a person down a flight of steps, we don't put them in jail because they weren't conscious of their actions.

Now a person who is blackout drunk or exceedingly high on narcotics may also be incapable of understanding their actions. Applying the same logic, courts should not be able to prosecute someone for driving drunk of they were "so drunk" that they literally were incapable of understanding that they were "driving" or even that they were "drunk". Courts decided a long time ago that intoxication could not be used a defence because it creates a moral hazard. People consciously choose to become intoxicated, and they should not be able to use that intoxication as a defence against criminal acts they subsequently perform.

COMPARING CONSENT TO DUI

So is it reasonable to compare a woman's ability to consent to sex while drunk to an ability to commit crimes? The law says no.

Intoxication cannot be used as a defense to the commission of an offence. It's not that the law says "if you're drunk you're responsible for your actions", rather it says "we cannot excuse criminal activity because of drunkeness".

Consent on the other hand speaks to a persons ability to understand the nature and consequences of their own actions. Again, man or woman, a court will not uphold a contract where one of the parties was unable to consent to that contract. Similarly, sexual assault = sex - consent. If one of the parties in sexual activity is too drunk to provide consent to that activity, then the act is sexual assault.

I also need to emphasize the in order to lose capacity due to intoxication, a person needs to be seriously intoxicated. Buzzed or tipsy is not enough. The person needs to incapable of understanding their actions. This is a high burden to meet. The issue is that proving it is extremely problematic due to evidentiary issues.

I also acknowledge that there is a serious issue with sexual consent law right now because it has no answer to the question of "what happens if two incredibly drunk people have sex?" That's a real issue, and one that the MRM should be promoting. However, comparing DUIs to Consent to Sex is a misnomer. The law does not view the two as being remotely comparable.

-tldr Drunkeness cannot be used a defence to criminal behaviour for public policy reasons. Courts do not claim that a drunk person is able to understand their actions, but rather that for public policy reasons we cannot exonerate people for criminal activity while drunk.

Consent, on the other hand, is the dividing line between being a willing participant and a victim. Sex with a person who is unconscious is a crime because that person cannot consent. Sex with a person who is a small child is a crime because that person cannot consent. Sex with a person who is too drunk to know what they are doing is also a crime.