~snip~
There are different casinos, I know of a case where they didn't want to give a player his winnings in roulette because he made a bet and slightly touched the field of the neighboring cell, this is absurd but they didn't give him his winnings. There are also situations when such casinos won't let you out with a big win until you continue playing and lose some of it. But to avoid this, you don't need to go to such dubious casinos, I understand that not all cities have good casinos, but then it's better to play online than to go to such casinos and then get even more nervous when you can't take what you won with you.
Casinos are known to have a lot of security cameras and a lot of people watching every move of the people in there.
If they decided the person affected the play in some way, I think in theory it is fair, because players can cheat the casinos and they should be able to stop that.
Having said that, it might have been a case where the gambler didn't do anything wrong and got accused of something they didn't really do.
I guess they only check when the house loses, and they don't really care when the house wins.