I have seen them first hand screw it up. For example, rather than either fix the patch or move something server side. They just write a script that if an “impossible” scenario occurs, then a ban is triggered. One that I know happened in the past, we had a teammate who leveled too fast when ice turrets came out (little did she know PG was about to flood the whole game with them), but back then shards were hard to come by. The system assumed she was cheating since she used too many and banned her.
Here is where the fun begins, they gave her ice shards as an apology. So, she used them the next build event. Guess what? Banned because she had more than was theoretically possible.
I do not know all the details but there was someone recently banned for achieving too many gems without an IAP so the game flagged him and he was banned. Despite him having a fairly through record of how he achieved it but I guess that one has to be decided.
Seriously though…a lot of the really easy hacks are ignored it feels like and rather than ramp up the server capacity (because it costs more?) they just continue as is it seems. It feels like it mostly relies on player ignorance more than anything.