What would you do? #64 / Biggest $ pot won to date

Rush poker:

Full Tilt Poker $0.50/$1 No Limit Hold'em - 9 players
The Official DeucesCracked.com Hand History Converter

Hero (SB): $175.30
BB: $201.15
UTG: $136.70
UTG+1: $61.00
UTG+2: $113.15
MP1: $65.00
MP2: $22.80
CO: $44.75
BTN: $70.05

Pre Flop: ($1.50) Hero is SB with Kd Tc
5 folds, CO calls $1, 1 fold, Hero raises to $5, BB calls $4, 1 fold
Standard steal

Flop: ($11.00) 7h 5h 8s (2 players)
Hero checks, BB checks

Turn: ($11.00) 9c (2 players)
Hero bets $7.50, BB calls $7.50
If he's not going to take initiative, I'm going to go ahead and try to take it down

River: ($26.00) 6h (2 players)
Hero bets $13, BB raises to $188.65 all in, Hero calls $149.80 all in
So am I making this harder than it is? Is this simply a snap call? What would you do?

Final Pot: $351.60
Hero shows Kd Tc (a straight, Ten high)
BB shows As 9d (a straight, Nine high)
Hero wins $348.60
(Rake: $3.00)

I thought for a second or two about the HUGE overbet, and simply could not put him on hearts or JT... I think he's raising the turn as a semi-bluff if he has hearts right here. I also think he's raising the turn if he has JT - he wants to add money to the pot while he has an opportunity so that he can get more money in on the river.