Well, what happened in top gun is a flat spin and it usually happens because of a major disruption of the aerodynamic flow around the fuselage... It is a "dynamic" situation, happening while the a/ is flying usually at the limits of its flight envelope or in flight conditions that can be hardly modeled (like in the slipstream of other a/c).
One of thing that most of the pilots I know (including my bro) told me about that route is that meteo conditions there can be very harsh and it is not uncommon to find yourself in heavy turbolence, losing even 200m in a flick of your eyes.
As the report says, the AOA of the a/c was something like 35°, which is an AOA that only some fighter a/c can cope with, so... It was probably as I've heard in the beginning: turbolence, heavy turbolence that struck the a/c. But I think it was the first time that an a/c came across such heavu turbolence.