Stars $20...backdoor A high flush on paired board...did I miss a bet?

[ssnyc]

pretty early on so no real reads...I usually don't limp A6 suited but table had ben passive and I had just raised previous pot...

I think the line was pretty basic but do I reraise/push the villan's CR on the river? It went through my head that a set or two pair would've raised earlier in the hand so a boat seemed unlikely but still????? Seeing monsters or being catious in a small pot in the early levels? Also is there any point in betting the turn? Ddidnt want to get raised off my combo draw since pot was so small

PokerStars Game #11125912153: Tournament #56433615, $20+$2 Hold'em No
Limit - Level I (10/20) - 2007/07/25 - 10:15:36 (ET)
Table '56433615 1' 9-max Seat #5 is the button
Seat 1: --- (1500 in chips)
Seat 2: --- (790 in chips)
Seat 3: hero (1500 in chips)
Seat 4: --- (2200 in chips)
Seat 5: --- (1430 in chips)
Seat 6: --- (1550 in chips)
Seat 7: villan (1500 in chips)
Seat 8: --- (1630 in chips)
Seat 9: --- (1400 in chips)
---: posts small blind 10
villan: posts big blind 20

*** HOLE CARDS ***
Dealt to hero [Ah 6h]
4 folds
hero: calls 20
2 folds
---: calls 20
---: calls 10
villan: checks

POT $80
*** FLOP *** [9h 7d 4s]
---: checks
villan: checks
hero: checks
---: checks

POT $80
*** TURN *** [9h 7d 4s] [Th]
---: checks
villan: checks
hero: checks
---: checks

POT $80
*** RIVER *** [9h 7d 4s Th] [7h]
---: checks
villan: checks
hero: bets 60
---: calls 60
---: folds
villan: raises 180 to 240
hero: calls 180
---: folds

[Uniqueuponhim]

This is pretty much never a boat. No villain in his right mind is going to check a boat on the river after there hasn't been any action at all on the turn or the flop. Unless villain is a complete idiot, that CR is air virtually 100% of the time.