Not looking to start a lengthy debate on this one, but... while the 'sleep sex' scenes present in so many VNs definitely qualify as sexual assault, I think what happened with Jill is a definite grey area. The MC's hand ending up between her legs was an accident and not done through any action of his. The 'right' thing to do is obviously for him to remove his hand, but I have a little bit of a hard time seeing him laying still while she grinds on his hand in her sleep as '100%' sexual assault. Not that it's exactly what happened, but I could definitely see myself in real life in that situation panicking and freezing up, not daring to move for fear of her waking up and being really embarrassed.
If he had waited for her to fall asleep, and then put his hand between her legs and started rubbing, definitely black-and-white... as is... like I said, I think it's a bit more 'grey'.