T high good?

** OOPS typo in my original post. River was 9c. Hero has T high on river ***

I can't for the life of me figure out if this was a call bluff or a good call. During the actual hand I considered both as a substantial possibility, and hence tanked for an extra few seconds before making the call.

hand #1
live $20/$40 LHE 8 handed
Hijack is new player to game and is posting. He does not know me, but I know he is a thrill seeking action player who plays in the $100/$200 game. He loves to makes moves. Money means nothing to this guy; he drives a Lamborghini.
preflop: mucked to Hijack who checks his option, mucked to Hero in SB who completes with Th7c, BB checks (3 players, pot size 3 small bets)
flop: KcKs4c, check, check, Hijack bets, Hero quickly smooth calls, BB mucks (2 players, pot size 5 small bets)
turn: KcKs4c6s, Hero bets, Hijack tanks for less than 1 second and calls (2 players, pot size 4.5 big bets)
river: KcKs4c6s9c, Hero checks, Hijack bets, Hero tanks for 10 seconds and calls, Hijack mucks.

Who said limit hold'em isn't a fun game?