I'm sympathetic to this guy. At what point is it ok/not ok to question false info, or any information you are not familiar with? Ok, if he was being an @ss about it, that makes it different. All indications are that the FA's didn't know the difference between a voip & regular cell call and was conveniently told it was an FAA rule. He knew better, explained the difference, and asked to see the FAA rule against it. When they/he couldn't find it listed anywhere, the FA decided to just checkmate the guy. No doubt inconveniencing everyone upon arrival. Again if he was out of hand, that becomes a (the) justifiable issue for a police welcome.

Not saying I want everyone blabbing on voip calls during flights, but in the absence of an actual ban, the bottom line is this guy was using (his own) VoIP service on an approved device on the airlines own service.