[RobA]

If you are assuming this guy is solid then I think your logic is reasonable in the way you played the turn and the river.

But I think you may be making a bigger mistake by giving capper to much credit to start. Isn't it at least enough likely that this guy is a spazz that you have to bet your TPTK with a nut-flush draw on the turn. Sure vs. a range of TT+, AK then you are behind. But this is an unknown. Maybe he capped with T9s or KTs, or 55-99.

Once he checks the turn its obviously much less likely that he has TT+ or AK. So it seems likely that he spazzed preflop. If he spazzed preflop maybe he'll spazz with a bluff on the river.