That can't be it, he flipped out on my Lady Hawke. I still think he'll do it if you are diplomatic either in an earlier event or try to reassure him after his first quest. Zevox may not have triggered it if his Hawke tried jumping Ander's bones without provocation beforehand.

It would be hilarious if this conversation was random.

And Pyren, don't feel bad. Anders I feel had a good concept, just a lot of lines out of place. If nothing else, different romance options/squad mates for different people.