I have watched this video many times, and want to call your attention to something:
(1) In the first incident, the "back punch": BYU Player #7 (white shirt) backs into UNM's Elizabeth Lamberts (red shirt), perhaps unintentionally, but when she makes contact the BYU player gives Lamberts a sharp elbow into the left breast. At that point Lamberts responds with a shove and a reciprocal elbow (or forearm) across the BYU player's shoulder blade.
(2) In the second incident, the "hair pull": BYU player Shumway similarly bumps into Lamberts and this time - you may have to stop or even repeat the video to notice this - grabs and holds with a firm grip the hem of Lamberts's shorts. Clearly this prevent Lamberts from stepping away or pushing Shumway away. Lamberts promptly reacts with a logical maneuver - she brings Shumway straight down.
In sum, Lamberts's behavior was excusable if not justifiable reflexes to unpsortsmanlike conduct by BYU players.
In my opinion Lamberts, being suspended from the team, is getting a raw deal, possibly the rawest in women's sports since Zola Budd was blamed for Mary Decker's fall.