2002 Audi Allroad Check Engine Light After Allroad Rear Imp

Hello,
I'm having issues with my insurance (AAA) not wanting to cover sensor repairs caused by a rear impact. My check engine light was triggered when my Audi Allroad was hit from behind, car went under the back of my car and tailpipes were hit but not damaged. Audi say cause of check engine light is O2 sensor (on exhaust manifold - I think), cost $800+ to diag and repair).

Other changes after accident: Car running noticeably rough, especially during idle; and front air bags deflate all the way immediately on engine being switched off, this did not happen before.

Can I prove to AAA that these issues were caused by the Accident? Very frustrating that AAA only covers the physical damage and not other difficult to prove damage.

Thanks!

Ian