In that situation that occurred in the game, the optimal solution in my view is to repeat the turn with all heroes, excluding the move past the shifted GO.
Moreover, the rules for conducting tournaments on ХВ directly state:
A host's decision can be appealed to a judge, and the judge's decision can be appealed to the AC. In fact, Dark is appealing the host's decision, who did not accept the tournament judge's ruling — this is what I see as incorrect.
And my suggestion regarding that time should be understood as follows:
If the encounter had happened on the next turn, and Dark was moving along his planned path down for the gold, then given that the second GO is visible, it would no longer be possible to consider the violation unintentional, and in that case my decision would be a technical loss. And then Dark would have been appealing that decision.

UTC+03:00, icq 593626431