A single hacker with Leonardo Da Vinchi class insight isn't impossible , a more ordinary cracker team is a lot more likely.
Any small time perpertrator who got very chatty about it would be found reguardless.
To me the best reason to disbelieve the braggart is that he is bragging, his claims arn't impossible but seem like a good thing to keep quiet about.
On the other hand , assisstance from Russia doesn't seem unlikely in any respect , I havn't seen any proof that Iran had help , I would not feel surprise tho if I do.
I don't think it necessacery that any code was cracked , the interruption of the instruction stream would require jamming on most of the frequencys that the frequency hopping scheme used , this would requie loud, not sophisticated.
Without instructions the automatic pilot might could have flown home on inertial guidence, but if it detected a GPS that it understood it might default to it , this being the software we should change before there is another chance for them to do this.
If our codes were cracked that would of course have also worked quite well, I only hope that we don't have an inside guy that could prevent us from having dependable codes. During most of the Vietnam War we were betrayed for thirty bits of silver and we will never know how many men were lost as a result.
Untill evidence of some sort becomes public we may just have fun speculating.
