War Thunder Full Auto Main Gun Glitch

Here I recorded my friend in a custom match with an full-auto main cannon. Somebody else had been using it earlier and we banned them because we thought they were hacking. He says he didn't do anything to trigger the glitch, his main gun just became full-auto. He has no modifications to the base game. This appeared only in the custom match.
Here is the view from the ground: • War Thunder Full Auto ...