In my eyes, for the purposes of this game, a "counter" is a Pokemon that can switch into a Pokemon, and, assuming neither Pokemon switches, that counter Pokemon will end up with at least 1 HP, and the other Pokemon will be fainted.
spiderweb is right Age of Kings, you're supposed to be able to take a hit from any of the moves (which includes stone edge in this example) and then OHKO the other pokemon while surviving. So I don't think that would serve to counter Heracross