Without consulting the rules, here's how I would rule, and why.
"Check" is binding. "Raise" is not.
Is his intentions really to raise if the button bets? Or did he mean to bet, but misspoke when he said check? In either case, check was the first thing out of his mouth, and is binding.
The raise part is not binding because it is similar to a third person betting out of turn. If the button bets, then the action changes, and any out of turn verbal declaration is no longer binding.
As a floor person, I would have to think that the UTG knows these rules, and might be angle-shooting, and therefore should be given a penalty. Or at least a warning.
If I was the button player, I would not ask for a ruling, but make a bet and see what he does, and, even though I think I know the ruling, ask for a ruling only if he doesn't raise. Or ask for a ruling after the hand is over.
Note that I feel this is one of those rare situations where the floor person might be obligated to refrain from ruling until all action is complete.