Only times I have seen things to this extent is when the truck has been in deep water. Seen it on my buddy's F150. Another buddy's ram 1500. and few people on here with their trucks after they went off road. My alternator on my truck just went out 2 weeks ago. just up and quit. wasn't causing me any kind of issues. But it has been known to happen. Just not like this. I would dig into it and see if he doesn't say something to the affect of he took it off road.