Yeah he has a 9 here always
Does he? I mean, it feels like he does, but am a bit confused by the 'overbet' thing, isn't he effectively betting 6.8k into 6.9k, given hero starts the hand with 9k? And once UTG and hero have both checked, neither of them ever have a 9, and button has to have either an ace or a 9, so he should shove regardless, no..?
Pretty sure you can never call here anyway, but if you were considering it you'd be better shoving yourself, wouldn't you? Though I think it's still extremely hard here to find a scenario where shoving is profitable.
On a similar tack though, if you were considering calling a bet of 2-3k on river then aren't you better off bet-folding (to the button) 1.5k (or even slightly less)? Since that includes the 9 in your range, so he can't raise with the ace.