Don't need the phone to track calls made, and where the recipient was located, just the phone number. These must have been the dumb ones who didn't dump their burners when the s*** hit the fan.
This current phone was not their “burner phones” .. it was their officially assigned WORK phone. The company made the mistake of not setting up the phone correctly .. if they had, then the company could have easily accessed the info on the phone. [I hope the company has learned it’s lesson.]
As for “burner phones” .. they were erased; smashed; and dumped into some body of water (I have forgotten where).