It's rare to see someone that creates multiple accounts in one casino for some reasons like forgotten password and email.
If you forgot the password or the email and you've done KYC for that casino, the best way to proceed is to contact the support and let them know your issue; they will guide you on how to proceed in this case.
Creating another account should have a good intention and not try to abuse; it is hard to cheat the casinos; they have an intelligent system that tracks and perceives your intention.
If that's a valid reason, the management will find out. But if there is some abuse that's done, they'll also figure it out. There is no way out for these abusers to hide into those reasons because no matter how hard their true intent, there will be traces that will be found eventually.
Although they sometimes create an error that the admins need to manually verify.
I've seen some cases that are genuine with this reasons but admins or staff don't verify them correctly and sometimes it does happen that there is a mistake on their end.