check in dark a collusional move?

[KHALI]

Recently played in the Alladin's 7pm tourney which I was lucky enough to win. I say lucky because at final table blinds were astronomically large, such that even as chip leader I was all in or fold for any hand. Here is the situation, we are down to 6 players and I am in SB with 9c6c and the short stack UTG+1 goes all in for a bet which does not equal big blind. Knowing the range or hands he could have I think it is correct for me to call but I don't really want to invest any more here. BB checks and I instantly call out check in the dark with the intention of sending message to BB that I will check it down. I know it is often an unwritten rule about checking down to eliminate a player but is this out of line?

Second case I had floor manager called on me. At the Wynn playing 4/8 while waiting for a 8/16 to open. I bet out on flop with a OESD and pick up a flush draw on turn so I bet again and am called both times by decent player on my direct left. River is a total blank and I figure only way to win is to bet so I count out my chips(8x$1) near the rail and gather them up and move forward(no commitment line here). As I do this he beats me in pot. I then check with my chips in hand and fold . He loses his mind at which point another player says it is not a bet but dealer is unsure??? Floor listens for two seconds and says no bet. I really didn't care for $8 but this tilted the guy so bad he threw about $150 in my direction over the next hour trying to bust me. How out of line is this and the dealer told me that soemtimes a forward motion is a declaration of a bet. What is this rule?

My intention was not to angle shoot but once his chips beat me in I would be stupid to bet a bluff. My bad or a good lesson for him? FWIW I am usually a player who tries to be friendly at the table and not creat hostility although this worked out in this case.