I think the glitch's been noticed before, but when you kill a jackal sniper it leaves the after image of the shield.
When you're doing the city level and there's those floating jackal sniper platforms if you get in one and the dropship attacks you with the plasma guns it'll knock it off, and if you move into the middle of the downed platform it'll push you away, and if you go to the blue thing that you stand on to get pushed up there in the first place it pushes you away, too.