Is Cobra coming back for a second time?

That's utter nonsense. I have a counter-proposal. Let's not fantasize, but rather assess what actually happened.
Regarding the term "maphack."
In this case, the player couldn't control their curiosity and, in front of the judges (i.e., clearly assuming that the opponent wouldn't object), made a move that they would definitely repeat after saving the game (no one would allow them to not repeat it, I'm sure they had no illusions about that). This way, they saved 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.