And it is easy to see why that is the case, if you win big in slots as long as you did not cheated the system in some way or form then you just got lucky and as such there is no reason for any casino to do anything, because as long as you keep gambling sooner or later they will recover that money from you due to the house edge, but this is different when we are talking about sports bets, because even if there is a house edge it can be overcome with expert play, so someone which is an expert at a particular sport could drain their coffers without any ability for the casino to get their money back.
Well you're right, for slot games it's impossible to cheat unless he's a dev team from the provider I've seen cases like this
The most common is in sports betting because it is very possible for gamblers to make deals with athletes/players to determine the final result
If the casinos don't realize it, their funds will continue to be drained this is the most common case.
It sounds impossible but I think I've heard few cases where players are accused by casinos to take an advantage from a glitch in slot game. Even though I do not really know about that cases clearly but I think this case is still possible to happen where players are able to cheat the system in slot games. However it is rarely happening and I'm sure most providers now as well as the casinos are well experienced enough to minimize it.