Your mule got banned for being a mule. Yes, you didn't bot on it but that's usually the offense that's given to accounts being used as mules for bot accounts.
For what its worth, my clients would also shoot up to 1GB just as his did on .118 whereas it wasn't doing it on the previous version. Had to use -mem to fix. So maybe it's not his script and rather the new client version, just saying.