I do NOT see how the 8 flange bolts came out, they are self locking, torqued nuts, yes 1 or 2 but not all 8, once loosened they would spin as a unit because of the lock nut, also that mess would have been slinging oil every where long before anything came apart, then there would be quite a bit of noise as well, This almost looks like someone pulled the drive flange or in another words STOLE it OR SABATOGE.
The carter pin had to go, then the torqued nut had to loosen just to let the pair of joined flanges (which would TRAP the drive flange retaining nut) move back enough just to clear the pinion shaft, at this point, there would be so much NOISE that things would come to a halt, with a GOOD chance of a BUNCH of COLLATERAL damage from the flying driveshaft.