This is standard practice among wireless providers - the Verizon dude is not new! Infact, there is a whole sub-industry based on this engineering task -called ‘Optimization’. There are ‘drive test’ tools out there that capture detailed wireless protocol messages by setting up phone calls on the devices attached to them and a laptop computer. These are then reviewed by engineers, like myself, back in an engineering office to try and solve network challenges - dropped/blocked calls, coverage and capacity issues.