I've played games that accurate... but it's because my opponent's position was terrible and the best move was often capturing something for free.
So depending on the complexity of the game and their rating it's possible... but it may also be a clear indication of cheating, yes.
I played a game against a player rated below 1400 in a line I knew fairly well. I lost. Upon computer analysis the player selected THE best move 90% of the time. I wonder if grandmasters are able to do this let alone a sub 1400 player. Is there any other explanation for this happening except for the player utilizing a chess program. I am really curious. Thanks for your input