^ What he said, there has been hundreds of hours spent on developing this anti cheat system and it has been accurate over the last several years, This removes the need of an admin in most cases when someone is blatantly hacking.
You can bypass VAC, but you can't cheat third party developed anti cheat systems.
Also I am not sure why people share accounts, let this be a lesson to others if they ever consider sharing accounts.
You live and learn, good luck on the next server/community.