Don't take my word for it, read an expert's opinion on the matter: https://gbatemp.net/threads/psa-why-the-jigs-are-a-bad-idea.505411/Maybe a month ago a botched installation of CFW happened to one of my buddies and the switch had a hard time powering on I had to literally hold the power button for 30 seconds for it to cut on I honestly thought it died. It wouldn't reconize RCM for almost 20 mins. So hypothetically speaking is there going to be damage to the right joycon rail for using the jig alot?
As for what happened to you friend, its too vague to make it sound like an AutoRCM issue. It sounds more like user error.