Would a scarfed ditto against another scarf'd mon not always speed tie? Simply because ditto would copy the speed stat, then get the same scarf boost the opponent has, effectively making both pokemon the exact same speed. I don't think it has anything to do with a mechanics tweak. They confirmed it was 50/50 (speed tie), so I didn't really understand your post on why you think the hihirudama would outspeed him; it was likely luck that the guy outsped him 4 times in a row, not a metagame twist.