mmmmmmmmmmmm it would depend on when she says it. Yuuya, as a general rule, doesn't really remember what happens while he's in berserk mode; he depends on what others tell him afterwards to know what happened. On top of that, he tends to be very avoidant on a few specific subjects, and this is one of them.

Not to mention the fact that, immediately afterwards, he is going to be a crying mess; he likely won't remember anything specific from the point where Shun fucks shit up, to the point where he wakes up the next day.

But yeah any sort of negative confrontation is likely to make him run away, at least until Gon comes back.