Was the game two weeks ago also played online? If so I can see cheating using AI.
If it was live, I guess then it could be cheating if Niemann had hacked Carlsen’s emails or perhaps practice games on the computer.
If the game was live and face to face, I don’t see how he could have cheated, I doubt he was wearing an earpiece or had someone signaling him the next move, I guess it’s possible but highly unlikely IMO.
What Niemann might have done is practice against a computer engine that could look at Carlsen’s moves over some number of games he’s played and offer counter moves that Niemann employed.
I’m just speculating.
The Chess Federation has a very rigorous protocol to prevent electronic cheating or spectator-assisted cheating in live tournaments.
Almost everyone who thinks Niemann cheated in the first game believes that a computer hack or a betrayal by someone on Carlsen's prep team was involved.
I have wondered if there is Internet or Crypto betting on chess matches?
Carlsen playing white against the weakest player in the tournament would have a huge pay off if Carlsen lost.
Or was receiving signals from an accomplice running a computer simulation