Alright, let me give some context.

This morning, I get in and find a project that didn't go out on time a few weeks ago (we usually aim for one a week, for each client). Now to be clear, it didn't go out on time because I fucked up; just been overwhelmed at work lately, and didn't realize I'd missed it (I've been covering for my friend/supervisor the past two months; long story short... he had a baby, and they don't think he's going to make it).

Because there was a gap in the schedule this month, I just figured I could slot the project into a blank week, which basically would mean everything is still on track.

Because my peer (who also vaguely works on the project) is out of town, I sent him an email, just confirming the update schedule looks good.

Lastnight, he shoots back a pretty stern email, asking why it didn't go out on time, and more importantly, why he wasn't informed sooner.

That, in turn, put me on the defensive. And I'm fairly meek.

I just say there's no excuse, the fault is totally on me, I've just been overwhelmed.

His email wound up making me... well, feel something. Panic, dread, anxious. Moreover, I felt like I was "answering to him", when in reality, he is barely involved with the projects, and is a peer, not a supervisor or anything.

In some ways, I kind of respect the sternness as kind of a "power-move". And really, it did respond like kind of a people-pleaser. At the same time, though, it also feels kind of dick-ish, and makes me less eager to work with him in the future.

HERE'S WHAT I'M TRYING TO GET AT...

In an office environment, where you're definitely not top-dog, how do you navigate in such a way you don't get walked-on, without risking alienating people you need to work with?