"If Iron Barbs causes both the user and the attacker to faint, then the attacker will faint first."
Yeah, I've tested it on 3DS too and Ferrothorn's user wins, no doubt about it.
However, as far as I know, XY OU does not follow 3DS' rules (Im sorry if it does, but I've searched about it and couldn't find this written anywhere).
It is a tie in Pokemon Showdown for XY OU's mechanics.
So why isn't it a tie in this tournament too, if the simulator the tournament follows says it is a legit tie?
People might say it's a "glitch", but "glitches" are just part of the XY OU's metagame.
In Shoddy times, people abused Sleep Powder + Spikes Roserade and I've myself abused HP Fire 350 Speed' Latios in many SPL battles.
And this is all fine, because if you can do it, it means they are part of the Tier.
What is or not a "glitch" is very subjective when there is nothing written about it, so I believe this semifinals' XY OU game should be a tie.
It's also written in the thread that "the tiers for each metagame are locked at the time of this post".
So if it isn't written anywhere about XY OU "following 3DS rules" or covering "who is the winner in each of the Tie game's possibilities" by the time of the post, then the XY OU game of the series should be a tie as Pokemon Showdown says it is.
(...)