First, while it's possible that with Russian or Chinese assistance (and they'd be more than happy to provide it for a share of that technology prize), Iran would be able to effectively jam a control link, I think it's very unlikely that it's feasible to actually gain control of it via the encrypted command channels. As others have pointed out, even basic 20+ year old U.S. comms equipment uses very, very strong and well-implemented crypto (complete gaffe with video feeds on earlier drones notwithstanding, even on those the actual control was encrypted). You have to figure Iran may well have spent the last year or more monitoring these missions (bistatic radar is especially suited to countering stealth when you know your opponent's likely flight paths) and experimenting with jamming techniques. Against an eyes-on-ground-oriented surveillance platform, the most practical thing to do might be to simply jam its uplink, then literally "sit on it" with another aircraft, gear-down, to force it to soft-crash mostly intact. A little crazy, but we've seen stranger and more creative things in the intelligence world, especially from 'technically inferior' opponents. Second, would you really send your most-current stealth and sensor technology out on mission after mission after mission, knowing that simple mechanical failure is a statistical certainty? It certainly wouldn't be the first drone (or the second, or the fifth) downed for whatever reason. If we didn't learn from the EP-3 incident near Hainan island, and the RAH-66 downed in the Bin Laden raid, then we've got a more serious and fundamental problem. It stands to better logic that it's either A) Effective-but-deprecated technology suitable to the mission risk of loss, or B) It's a counterintel operation, with deliberate, subtle defects in various bits of technology which will no doubt be replicated in excruciating detail. Brings to mind the Siberian-pipeline sabotage in the 80's.