Air Bag Not Deploy problems of the 2004 Volvo S60

My son was in a side impact collision on the passenger side of his 2004 Volvo S60. He was in a rural area and either didn't see the oncoming car or missed his stop sign and the oncoming driver was unable to stop. The other driver is uninjured but my son in severely injured with a grade 3 dai head injury. He was wearing his seat belt. The side airbags deployed but not the one in the steering wheel. In an email Volvo told me this is how the airbags are designed and that the driver airbags will not deploy on side impact. If that is correct information, this needs to change. The only significant injury my son has is where his head hit the steering wheel, if that airbag had deployed his injuries would have potentially been much less. The airbags are already there, I don't understand why they can't just deploy on any significant impact. I will include pictures.

Tl the contact owns a 2004 Volvo S60. The contact stated while attempting to make a left turn, another vehicle intersected her line causing impact to the front driver's side. The air bags did not deploy. The contact stated that the abs warning light was illuminated prior to the accident. The contact stated no one sustained injuries or sought medical attention. A police report was filed. The vehicle was not drivable. The vehicle was towed to an impound lot. The vehicle failure had not been diagnosed or repaired by a dealer or independent mechanic. The manufacturer had not been informed of the failure. The failure mileage was approximately 162,000.

I was driving 35-40 mph when a vehicle 2 cars ahead of me had to make a quick stop. I did not see this happen in time, slammed on my brakes and consequently smashed into the back of the car in front of me, who then hit the car in front of him. I totaled my car. The passenger air bag deployed and filled my car with smoke (or whatever that is) however, the driver air bag did not deploy. I was rushed to a trauma center and my injuries include my back, neck and I lost a tooth from my face hitting the steering wheel. My chest and legs are covered in bruises from the seat belt. I am very lucky, however I do not like to think of what could have occurred if I was at a high speed and on the fwy. And the air bag did not deploy because it was defective, and perhaps it was not designed to go off in this particular incident? I hit head on, no logical reason to think the passenger airbag going off as it did, but not mine or driver side.