Air Bag Not Deploy problems of the 2004 Volvo XC90

My husband had a 55mph crash in my 2004 Volvo Xc90 on the freeway. He rear ended another driver at top speed, was spun around several times on the freeway and ended up facing traffic. The passenger side airbag deployed, but the driver's side did not. The inspector from my insurance company said there was not reason the driver's side airbag did not deploy at that speed, other than a defect, as far as he was concerned. I contacted Volvo and was basically given the run around about how the airbag should not have deployed and that this was perfectly okay. I would like an investigation especially since my cem system was not operating properly prior to the accident. I had airbag warning, brake failure, etc. , and the dealer told me a year ago the cem system was not working properly and needed to be repaired at $1300, which I was not willing to pay.