So when we get a big win, we need to validate with the slot providers everything is ok, then we pay out.
(many times slots can be hacked, so again its the bad guys making it hard for the good guys)
We send a request off to these guys mentioned ^^ but then we are THEIR customers.. so if they don't get back to us for the weekend, we can't get back to you.
Big wins and big withdrawal requests must be verified carefully before processing. It makes sense because at first, casino must do a right thing and should not let cheaters succeed with their works. And second is important too, as a business the casino must avoid loss to cheaters through big wins and big withdrawals.
Your explanation is also insightful about how things work between the casino and a game provider with tight collaboration and support each other to keep up good business for both sides.
Lastly weekends should be expected with slower support response and things would be handled at normal speed on non weekend days.
That is true, if there is someone who tries to just withdraw right away and a huge amount after just a few games, its not going to be that good.
However, this is sports betting, which means that it should be lesser chance for them to do anything, you need the games to be correct to win, and you can't just guess it correctly by cheating somehow, you need to actually wait for the game to be over, the only other possibility would be abusing some loophole in the code to get the hot wallet and that would not be really based on any game result at all. They do have some strong safety and never seen them get hacked or anything like that, so I am guessing that whatever they are doing to prevent it, must be working very well without an issue.