It is really easy, either he is logging all the miles on foot alone or someone else is sharing the running with the same watch. There is a slim chance of being in a moving vehicle and faking the data. The only way to be sure is an operation like Laz and his crew over many days and examining the resulting data.
Do I know either way? No.
Repeatedly stating that nobody has any suggestions when this really obvious one has been stated before is yet again extremely reminiscent of Litton/Rossi/Meza. The behaviour of someone completely above board when accused of something is amusement as they quickly demonstrate what a fool you are for doubting them. It is not hostility and rock throwing.