The thing is for that scenario to have happened, the thing would have simply crashed. Then yes, you can go with the whole "$h!t happens", reasoning. But for this you have to buy into that the Iranians have the technology to not only intercept this thing, but then to take over control with enough sophistication to actually navigate it and land it. That's hard to buy considering the long list of recent failures they've experienced with all of these explosions they've been blessed with.
If there was a failure on our part, why on Earth would we put coordinates to an Iranian airfield for it to make an unassisted emergency landing on it's own? That makes even less sense than the Iranians intercepting it.
As I posted before, my understanding is that the programmed "failsafe" default is a controlled landing, nearest airfield in its memory would be the obvious place to do that.
I suspect the input of lawyers over ruled the common sense of operators.
The people who actually work with it probably said "Lets rig it to blow itself to bits" and the lawyers screamed "But you can't do that ! A piece might hit a civilian !"
Completely overlooking the fact that if we gave a rats ass about those civilians we would not be considering bombing their sh!thole country.