I agree men have a bigger responsibility in ensuring they aren't assholes towards women they're interested in, but your example here to support your point is highly contextual.
In the case of the OP, the woman in question was friends with him. He wasn't some random stranger on the street catcalling her. That relational context provides a stronger basis for her to have to courage to say no clearly and concisely without fear of retaliation, because of the assumption that both parties wouldn't want to jeopardise the friendship.
When the man in question is an unpredictable unknown quantity, I can totally get women feeling fear of reprisal if she responds to his sexual advances in a negative way. On the other hand, if there is a preexisting relationship/friendship, there's far less reason for the woman to be fearful unless she's such a poor judge of character that she'd willingly choose to be friends with a dangerous asshole.