The game decides that ganon ties at best or loses at worst when he forward b's you off the edge. Most of hte agreement in this topic is that the win should be awarded to ganon.
I don't agree that he should lose, as its a "chance" that he either ties or loses. I dont like the idea of chance or luck in this game. However, I wouldnt give him a win either. Id say take it to a tiebreaker. Other characters have suicides or fancy way of finishing people before plummeting to death, its just a matter of who dies first. If a DK grabs someone and jumps off the edge, but the enemy releases before the floor and DK dies first, should he win? If a Wolf side-b's an enemy off stage, and dies first under the stage, while his enemy didnt die to the side-wall initially, but will die to the floor as well since he cant make the recovery, does Wolf win too? Its all the same thing, except Ganon's move ties the two players deaths closer together. The move is implemented as it is for a reason, that reason I'm sure the Devs has discussed or will address in the future. As it currently stands, it is meant to be this way, so that is how I choose to regulate my rules. I am no game balance developer, and judging by how well the devs are doing now, I trust they will do right by this game. If they changed it to a Ganon insta-win, then I will accept it, as I'm sure they have their good reasons for doing so. Ganon shouldnt lose the match, but he also shouldnt win. Take it to a tie-breaker (1-stock match, same characters, same level).
Keep in consideration, this is all just my opinion. I dont believe anything anyone says here as fact of being true or false, including me, its all just speculation.
I do thank you both for pointing that out, that scenario wasnt what I had imagined when I said "double knockouts," what I was referring to was the examples I gave, i.e DK grab jump, a super low falcon punch off-ledge that somehow ended in falcons death first, two players smashing each other one stage in which both die almost simultaneously, yet one just before the other, stuff like that. Whatever the case, I'll definitely have to re-word the rules for those special scenarios. =)