I think the call of the flop check-raise really limits him to top pair+ hands, and huge combo draws. Calling the turn bet kind of seals it right there. He doesn't have any two pair hands except QTs which is still very loose!
These are the main hands I see calling a flop check-raise and makes it to the river:
AdKd beats u
AdQ would check back
AdA would check back, I think there is a non-zero probability non-diamond AA folds on turn
KdK would check back, I think there is a non-zero probability non diamond KK folds on turn
KdJd beats u
Jd9d, 9d8d beats u (but might be too loose for a tight player UTG)
QQ,TT,77 less likely since they should've raised u hard on flop or turn.
QTs chop!