Is it okay to cheat in football?

The goalkeeper, Manuel Neuer, grabbed the ball and put it back into play. Neither the referee nor the linesman, both of whom were still coming down the field - and thus were poorly positioned to judge - signaled a goal, and play continued.
After the match, Neuer gave this account of his actions: "I tried not to react to the referee and just concentrate on what was happening. I realized it was over the line and I think the way I carried on so quickly fooled the referee into thinking it was not over."

To put it bluntly: Neuer cheated, and then boasted about it.
By any normal ethical standards, what Neuer did was wrong. But does the fact that Neuer was playing football mean that the only ethical rule is: "Win at all costs"?