To make it fraud requires two things. First they need to be breaking some kind of legal agreement, secondly they need to use deception to make it seem like they didn't.

In this case it's debatable to what extent they're deceiving anyone, but more importantly all they're doing is pressing the slot button at the optimal time, which is kind of the point of the game. Now most people wouldn't consider this 'fair', but for a legal argument that is a bit vague, even if it might be enough to say, disqualify someone from a tournament.