BB hand

[BobboFitos]

Posting this for a friend because he wants to hear opinions. Home game 1/2 NL, table is 9 handed.

Hero is in the BB with 42o and a stack of 135$. Is known as a tight (and possibly passive) player.

UTG (solid, 110) limps, MP (biggest fish in the game, plays most pots, 75) limps, SB completes, Hero checks.

Flop: (8) 9 5 3 rainbow
SB checks, Hero checks, UTG bets 6, MP calls, SB folds, Hero calls.

Turn: (26) 2
Hero checks, UTG bets 16, MP calls, Hero calls.

River: (74) 2
Hero bets 40, UTG pushes, MP folds.

Hero calls.

He wants to know what people think.

[DJSirMatthew]

I would not do it. There is a strait draw, a full house possibility, and a higher kicker for 3 of a kind. If this guy is a true rock it just slams the nails into the coffin. The full house, in my opinion, is the most likely b/c he probably bet with high pair on the flop, this is because 6, although small, was nearly a bet the size of the pot. This may have been a bet to push out any draws to a strait. I think that he made 5’s up on the turn because he made another large bet.
Three of a kind with a bigger kicker is pretty unfeasible because he wouldn’t of bet on the river with a gut shot strait draw to the 5.

What did the bettor have in the end??