[skp]

Hm...not quite sure that this is a routine fold...

While I think that it's the right play for the button to just call on the flop with Ace/no kicker (i.e. auto raising as most players would do with an Ace may be less correct in a heads-up draw bereft flop), it can also be the right play for him to call with any pair. So, I would probably bet on the turn (of course, you know this local - I don't).

Having checked the turn, the river checkfold is probably correct.