Video of the incident: http://www.liveleak.com/view?i=27f_1424196366. The TV host lacks the masculinity and social status of the surfer who had just won the Australian Open of Surfing, so he is already at a disadvantage before the situation even begins.

Regardless of how the surfer got her number, what the texts actually said, and if they actually made her feel uncomfortable (and an educated guess would be a. she gave the surfer her number, b. the texts were flirtatious, and c. she used "feeling uncomfortable" as an excuse for why she didn't shut the conversation down), attempting to defend her publicly was a huge mistake by the boyfriend. The boyfriend continued the epic fuckup by making a ridiculous post on instagram with the hashtag #sheistaken. The model's response on twitter implies embarrassment with her boyfriend's public white knighting.

The takeaway message is that if you're in a solid relationship, and have the respect of your girlfriend she needs to shut any situations like this down right away. To be fair, men are much more physically intimidating than women, and social pressure can cause people (both men and women) to carry on conversations like this longer than they want. My own personal opinion is that if I were to run into a situation like this for the first time with a young girlfriend, and texts from her side showed no interest or were attempts to shut the guy down gently I would explain that his behavior is disrespectful, and that she needs to be straightforward and blunt, and end the conversation and block the number. If my girlfriend were older, I would expect her to know how to handle the situation already, and would probably take it as a sign that she isn't relationship material.