2011 Cadillac SRX drivetrain & axles problems

Tl* the contact owns a 2011 cadillac srx. While the vehicle was engaged in park, it rolled backwards on its own and struck another vehicle. The contact was seated in the front passenger seat at the time of the failure. The air bags did not deploy. A police report was not filed. The contact sustained injuries to the shoulder that required medical attention. The contact was not provided any specifics regarding the diagnostic or repairs. The contact was not sure if the manufacturer was contacted.

The rear differential has failed. The warning light came on, so I took my car in to be checked. The part has been on back order for 3 weeks and I am now being told it will be 2+ more weeks before I will hear anything, along with all other GM customers in the country that are waiting for this part. I have been told by cadillac there is no specific date on its arrival. Should this not be a recall item if the part is not available for this long? I am not sure how many people are waiting for it as of yet.