Did the FBI have the evidence that he had actually hacked a previous leg of the flight, or did they not?
If they did not, if they knowingly programmed a suspect with false information, they are guilty of attempted witness tampering through false memory syndrome. Lots of work on this, you can program anyone to believe they've done anything even if the evidence is right in front of them that nothing was done at all. Strong minds make no difference, in fact they're apparently easier to break.
Falsifying the record is self-evidently failure of restraint.
I have little sympathy for the researcher, this kind of response has been commonplace since 2001, slow-learners have no business doing science or engineering. They weren't exactly infrequent before then.
Nor have I any sympathy for the airlines. It isn't hard to build a secure network where the security augments function rather than simply taking up overhead. The same is true of insecure car networks. The manufacturers of computerized vehicles should be given a sensible deadline (say, next week Tuesday) to have fully tested and certified patches installed on all vulnerable vehicles.
Failure should result in fines of ((10 x vehicle worth) + (average number of occupants x average fine for unlawful death)) x number of vehicles in service. At 15% annual rate of interest for every year the manufacturer delays.