Predator hammer melee backward damage

So running after predator, hitting him to back, while predator is hitting empty space on his front with hammer, fireteam members behind him gets damage even while hammer doesnt travel that direction

If they are doing the heavy swing, it does have a hitbox there.

Never actually used that thing.
Does it have an AOE?

Yes its aoe seems to be huge

Shouldnt, heavy hit is going from back, over predator and landing toward it