Is Cobra coming back for a second time?

Let's start by attacking the heroes just to take a look, and then attack for real :) LOL, that's nonsense...

Indeed, it's nonsense. I have a counter-proposal. Let's not fantasize, but rather evaluate what actually happened.
Regarding the term "maphack."
In this case, the player couldn't control his curiosity and, in front of the judges (i.e., clearly assuming that the opponent wouldn't object), made a move with the main hero that he would definitely repeat after saving (no one would allow him not to repeat it, I'm sure he had no illusions about that), thus saving 20-30 seconds of the 2500 seconds available. Formally, this is a maphack.
If the player secretly explored the map and studied it thoroughly in search of a path to victory, that's also a maphack.
For me, these are different violations of the rules in terms of the degree of guilt and the consequences for my attitude towards the player.