A plane flying over an enemy war zone and crashing is not unbelievable. Even while not under fire their protocols push the limits of a plane, plus the weather over mountainous terrain (rip Kobe), etc.
A militarily flight with only two people on it is not unbelievable. I once flew from Afghanistan to Germany on a C130 with the two pilots, me, and a bunch of broken down helos.
The Taliban taking credit for it is expected. They take credit for everything. They used to fire a few shot in the general direction of our convoys, then report over their radios that the ambush killed 5 Americans.
It's possible something shady went down, buts its also possible that this was just an accident.
More likely that than the Taliban shooting it down out of the sky. The Iranian government responded to the Soleimani bombing like a JV squad...now they're pulling off this shyt? Doubt it.