RifRaf3
I'm happy to keep juggled balls in the air. I consider the buried a/c scenario my lowest priority, but I can't rule it out.
I disagree with your assessment that the two are completely different, specifically regarding the physics. But fine, let us just move past whether it is even physically possible and instead move onto the second issue with the theory
If a plane did this, think of the force of impact that would be needed. (and we will just skip the waves and particle displacement, jumping straight to...)
The impact would be unbelievably strong, and certainly picked up on the many geological instruments in the region (including those of USGS) ~ China already proved to us there wasn't suspicious activity until 2 hours later though (activity which was later explained as being an earthquake off the coast of Sumatra)
Is all of it possible this all happened, while leaving zero trace of it happening? I guess theoretically, if absolutely everything went absolutely perfectly right - but it would be one of the more amazingly unexplainable incidents ever witnessed and therefore unbelievably unlikely.
Most likely? Someone who knew what they were doing did what they knew how to do - darkening then piloting the plane to a location we are unaware of (as the experts concluded off the known evidence)