The following is a quote from the article in the link at the bottom.

"...the scheme involved Benward somehow convincing casino crews that he placed bets on winning numbers after the numbers had already come in.

One thing that interests me is the borderline between cheaters and advantage players. One breaks the rules, the other looks for any possible edge without going over the line into straight cheating.

Benward was a cheater. He did a verbal equivalent of past posting. ..."


     I've "very very seldom" observed a Bac player cheating. The few times I've witnessed this is by the cheater moving their official bet back toward them and into the winning spot. Typically, as the dealer started paying out to the opposite end of the table. 



https://www.techopedia.com/gambling/blog/winners-losers-las-vegas-black-book