"If you can fly in the mountains, you can fly anywhere".......
Reno/Tahoe is an....interesting environment, for the pilot, year round.
Stead is in a "bowl", a well stirred one.
I lean toward elevator failure, as well. The right. The left elevator has stress attenuation (at the join/bellcrank) via the tab, the right takes more impact. The difference in load between the two is a chronic source of strain on the mounting cups at the bellcrank. I think the right elevator may have sheared, scrubbed some of the throughbolts that join it to the bellcrank. When it relaxed out of the airstream, the left elevator went stress critical, v/v the Trim Tab. Depending on the severity of the rotational failure of the Right elevator in its mounting, the LHS took on the load we see in Clipped Cub's image. The degree of torsional stress displacement of the tail would have unrigged the Tail feathers out of alignment with the wings and forward fuselage.
Permitted an extrapolation, this unrig makes the aft fuselage an emphatic right rudder, with sufficient input to recover the left roll, and roll the a/c back right. The fuselage recoils, and the a/c 'settles' into its ballistic path upward. It also recovers the Pitch Up, as the aft would be drooped, and deflected right.
This instant unrig/rerig suggests to me the loud noise heard at the time. The a/c at this speed is a drum, a skinned barrel, no different.