So, what, England quickly ran over to the umpires and asked them to not look up the rule? That's the only way it could be cheating, and not just an umpire error.If it weren't England, they'd have looked the rule up.
In any case, it depends on what they think "the act" that caused the overthrow is. If it is the throw, then it's a mistake. If the act that caused the overthrow is the ball hitting the bat, then it's fine.
Whichever of those you go with, it's still not cheating.