They're both in the wrong, and she did start it, but the dude took it way further imo, not that it absolves her in any way.
She sat on his chest, lifts his shirt and doesn't stop when he tells her to, only thing he has over her is size, but that's frankly irrelevant.
Him going straight for her ass just makes it look like he found his chance to touch her, felt really really creepy. Pinning her down when he knows he's stronger than her, not stopping when she asked him to and lifting her shirt all the way to her bra... Jesus dude, no misunderstandings here, whatever those guys think they saw was reality.
If we're using this moment as their realization that they're capable of feeling things for each other, then let's notice here that while the MC was capable of overpowering her, she was pinned down and forced into a panicked apology, whole chapter is just gross in every way, yuck.