What happens when someone wins consecutively from a casino? You already answered the question  I believe that most of the casino would flagged their account or at least they will keep an eye that user. Because consecutively is impossible, maybe win streak one or two times is possible but if you win like 100 times in a row I would say casino would watch you.

They might freeze your account and asked some question but I don't believe people always hit jackpot in game like Slot machine or lottery but in the card game the possibility is high