Here is the core question: Payday 2 does not show the tag above your own head on your screen. This is a notorious design flaw. You can be flagged as a cheater for an entire heist and never see the red text.
The game went silent. The assault wave ended abruptly. The music cut out. Payday 2 How To Know If You Have A Cheater Tag
You cannot see it yourself. You must: