What was the evidence indicating another individual was driving Thompsons car? Was it another surveillance or an individual? Was there mention of what direction the vehicle was going or if she might have been seen as a passenger? Did her son notice if anything was left behind that she would have usually taken if she were to leave. If her phone pinged in the area 800 miles away why is there no mention to as if there was a follow up?
If she was last seen at the bank, can law enforcement pull security footage from surrounding businesses to see what they can locate after she left the bank? It seems a good probability that it could have been attempted robbery if someone thought she might have cash.