I've stolen this hand from the MTT section, but is this the ISF theorem?

First level, about the 15th hand or so. No read on the villain. How did I do? When he 3bets the flop that small I'm thinking he either has 33, AT, AA or air here. Is my river check okay? Really, any bet on the river commits me if he check-raises all in. The way he played it I can't see him calling with much on the river if he doesn't have me beat.

PokerStars No-Limit Hold'em Tourney, Big Blind is t50 (9 handed) Poker-Stars Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

saw flop|saw showdown

UTG+1 (t10000)
MP1 (t9775)
MP2 (t9000)
MP3 (t10775)
CO (t10600)
Hero (t9925)
SB (t10225)
BB (t9775)
UTG (t9925)

Preflop: Hero is Button with 9 , T .
UTG calls t50, 2 folds, MP2 calls t50, 2 folds, Hero calls t50, 1 fold, BB checks.

Flop: (t225) 9 , 3 , T (4 players)
BB checks, UTG bets t225, MP2 folds, Hero raises to t700, BB folds, UTG raises to t1300, Hero calls t600.

Turn: (t2825) 7 (2 players)
UTG bets t2850, Hero calls t2850.

River: (t8525) 5 (2 players)
Dealer: UTG, it's your turn. You have 15 seconds to act
Dealer: Player UTGhas requested TIME
UTG checks, Hero checks.

To me, villain's range on that flop is JQ, 33, 99 and TT (both unlikely), JJ-AA, AT, and air.

By the turn since we really are only worried about 33 there
and our opp has committed so much of his stack + he likely has a hand (KK or AA) that he'll stack off with, we push.