The Valve Anti-Cheat is notorious for being poorly designed. There have been several instances when the anti-cheat has wrongfully caught a person afoul. When this happens to players at the top level, it is definitely a cause of concern for many. often times it requires direct communication with the game developer to lift the VAC bans. But its not as easy as said.
https://twitter.com/Chief_Sangy/status/990822316668956672
Australian team Chiefs’ CEO is definitely unhappy with Valve’s appraoch to the entire situation.