FFlogs uses its own way to figure out values, especially in terms of fight duration and such. I would also wager it displays effective HPS, so removes overhealing. It'd make little sense to track HPS if it counts every terrible healer vomitting aoe heals with 90% overhealing.
Oh also your parse is fucked. No way you killed Eden Prime in 4mins. It probably cut the fight during the transition since it's so long. So maybe it does count overhealing, but you don't have the right value for yours anyway.