Is this allowed in "real" casinos

[redleg319]

I used to play in an underground cardroom in N. Carolina. The following happened couple of months ago.

It was a NL table 5/5 500 max.
I get QQ in CO. MP player raises to 30, folds to me.
I re-raise to 80. BB calls and MP does as well.
Flop is A 10 6 rainbow.
BB bets 100, MP raises to 250. I fold, BB calls.
Before the dealer flipped the turn card, the BB asked the MP "chop?"

MP agreed, and the dealer split the pot. I asked the dealer WTF?? and he said it is allowed. I felt like collusion was taking place so I racked up and left.

Does this happen in the casinos?


Opinions??


PS. If I didnt feel cheated, I would have loved to keep playing, because the table was full of donators. But I figured I would eventually tilt because of the colluders.