Something doesn't smell right.
The FBI and other law enforcement provided the bomb and detonator? Doesn't that sound a little like entrapment to you?.
If he was working with a terrorist in Pakistan, he obviously only received words of encouragement or incitement, there were no reported tech support or logistics- no money. What you have here is an easily manipulated nutcase.
Granted there’s not much detail in the story , but if the FBI’s goal is to combat terrorism and not spoon-feed some rogue sociopath, they would have kept him on the hook and let an actual plot develop.