At least in the TV version, it's very clear. The movie edition might have sped up the scene for brevity.
It was a team of 3 MS, Zinin in unit 1 (Ahead, team leader), a no-name in unit 2 (GN-XIII), and Louise in unit 3 (another GN-XIII). Zinin is the one who chops off the Exia Repair's two arms and a leg. The no-name in unit 2 is about to spear the Exia Repair with its lance when Tieria shows up in the Seravee. No-name dies after trying to challenge the Seravee in close combat. At that point Zinin chooses to retreat and he literally grabs on to Louise and pulls her out of the combat zone.
Does the battle still play out the same way in the movie edition? I mean, is a GN-XII also destroyed by Tieria? In that case it cannot be Andrei since the only people left alive would have been Zinin and Louise.
How about afterward? Does Andrei still appear on Earth knocking on Sergei's door in an awkward meeting to "encourage" Soma to join A-Laws?