My computer apparently can’t read the video files so I’ll have to go through them one by one connecting my phone to the camera
VLC media player should be able to read them. But why did you buy a dash cam where you can't view the files? Seems pointless to me.
IN regards to the 400 miles. I would expect 20-30 miles top. And I would never consent to a tech taking my truck home over night. Where does he park? Is he a good driver? Does he smoke? Did he get fast food?
The number of miles wouldn't bother me, just what or how things were done during it. The service advisor failed by not keeping you in the loop.