6 moves in a row

I was playing a game in a tournament vs a guy I personally know, and after a few moves he lost by default. Apparently he had made 6 moves which was suggested by Stockfish, in a row, so the system said : "cheater detected"! So is that a thing, I didn't know about this, sorry, that's my first post. A link to the game lichess.org/THN984Mh/white#13

He might have opened analysis board during the game which i think causes the "cheat detected white/black is victorious"

I honestly think this example should only happen between lower rated players because stockfish would be surprised that such a low rated player made multiple perfect moves in a row.

#2 Probably
#3 Nope

It surely wasn't because of the moves. You were still in the opening. Lichess detected some other thing happening that it considers cheating.