When Bernie plays craps, he is shown placing two stacks of chips side-by-side on the pass line. This is incorrect - a player's entire bet must be placed in one vertical stack. AFTER a point is established, a player make "take the odds" by placing a second stack of chips BEHIND the original pass line bet. A second stack of chips on the pass line next to the player's bet would be assumed by the crew to be a toke - a bet for the dealers.
In a scene where Bernie is unlucky at the blackjack table, you see an empty table with the cigarette butts quickly accumulating in the ashtray. However, this would imply there were people at the table for a long period of time, which wouldn't have been the case if people weren't winning.
As the extras turn from the payout window when Bernie is in love and becomes "lucky", the dolly track can be seen on the floor and the actors are very consciously stepping through the rungs and looking down at it so they don't trip.