Not the casino so I can't say but personally I think that would make it easier for them to stop him because he made a conscious action of putting them in the pot.@ReallyGoodUsername so here is a question for you, if he pushed his chips in middle then lost and was grabbing his chips out of middle would they cash him out?
If he didn't move all his chips in he could claim he only bet $100 and didn't see the All-In chip - complete BS? Yep! But could it be fought in court? I'm sure some trolling lawyer would say yes and take the case.