Correct Fold on River?

PokerStars - $0.02 NL (6 max) - Holdem - 6 players
Hand converted by PokerTracker 4

BB: 73.5 BB (VPIP: 27.27, PFR: 9.09, 3Bet Preflop: 0.00, Hands: 11)
UTG: 100 BB (VPIP: 53.85, PFR: 46.15, 3Bet Preflop: 50.00, Hands: 13)
MP: 145.5 BB (VPIP: 42.86, PFR: 14.29, 3Bet Preflop: 0.00, Hands: 7)
CO: 70 BB (VPIP: 46.15, PFR: 7.69, 3Bet Preflop: 0.00, Hands: 13)
Hero (BTN): 75 BB
SB: 60 BB (VPIP: 61.54, PFR: 23.08, 3Bet Preflop: 20.00, Hands: 13)

SB posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has A♣ T♦

fold, fold, CO calls 1 BB, Hero raises to 4 BB, fold, BB calls 3 BB, CO calls 3 BB

Flop: (12.5 BB, 3 players) 3♥ 2♣ A♠
BB bets 4 BB, CO calls 4 BB, Hero calls 4 BB

Turn: (24.5 BB, 3 players) 6♣
BB bets 12 BB, CO calls 12 BB, Hero calls 12 BB

River: (60.5 BB, 3 players) 3♠
BB checks, CO bets 50 BB and is all-in, fold, fold

CO wins 57.5 BB

They're effectively repping trip 3s and the way they played would agree with that: limped in pre-flop so would imagine lots of junk with a 3, and they took a long time to call the turn bet. Did I play this right or am I missing something? Many thanks in advance!