Is saying "Check it down" collusion?

[dostofan]

Is this collusion:

I'm short and push all in late in trny and get 4 calls. 3rd caller says in chat "Lets check it down, right?"
(I had A6, flop ace and get sucked out by 67 on river. No one bets, not even trips 7's on river-but regardless of outcome this is either allowed or not allowed and I'd like to know)

Is this collusion or not? I was told it is and write FTP an email. What would happen if this was WSOP? What would FTP do about it anyway?

(If it matters, I would still be left with a med sized stack, but have a shot, or maybe at least cash higher)