collusion or utter stupidity?

[tdarko]

at the final table yesterday of a 30+3 MTT on Party, 10 players left.

Stacks:

UTG- 35K+ (possible colluder)
UTG+1-30K+
CO-3185 (possible colluder)

blinds 750/1500

UTG raises to 3000, UTG+1 calls, CO raises all-in to 3185, UTG thinks for 3 seconds and folds, UTG+1 calls.

the table starts chirping at the Villain who folded and he doesn't respond and two players say they are reporting it. it didn't die down for at least another orbit.

who folds this for 185 more chips? is this possible?

it seems very possible to me when i thought about it after the hand was done and thought it was fairly clever. CO has JJ, they are talking about the hand and UTG knows his buddy is pushing so he just wants to put some extra chips in there in case someone else comes along (plus it gets the action started) but doesn't want to force him all in so he min raises. UTG+1 calls, so CO of course pushes and this is where he folds and allows the Jacks to get heads up to triple up. now i only thought this would be possible if they were colluding, but it sounded possible in my head.