For sure! It's absolutely reasonable to believe that Hans beat Magnus completely fairly. It's also completely reasonable to believe there's a better-than-even chance that Hans cheated in this game.
There are a number of comments here which promote the idea that this is simply sour grapes by Magnus and totally uncalled for, and I find those perspectives to be overwhelmingly uncompelling.
I agree but Magnus also plays bad games once in a while. So it is not quite clear from a sample size 1 and a std deviation of infinite.