It is a GSX issue. Did the same to me tonight. Almost done pushing and my MD-11 jumped to 100 feet anf spun 360 then crashed to the ground. NEVER occurred prior to GSX.
As clearly explained in this post, IT IS NOT a GSX issue. Or, more precisely, GSX has REVEALED a problem with either your plane or the scenery you use. I'll repeat the explanation, again:
If you are seeing that ONLY at the end of the pushback, which it what your post seems to indicate (is not clear now if you are having that problem only at the end of pushback, of you are having it always, whenever you change views), than it's related to GSX, even if it's not a GSX problem.
The real cause of the problem is likely your aircraft.cfg that has wrong contact points that results in the airplane being unstable when its physics model is turned on and off, and I'm fairly sure it doesn't happen with every airplane. Or, the scenery has a small ground spike (usually caused by 3rd party meshes set with too high ground resolution, causing terrain spikes), which, combined with THAT airplane, is causing it to spin over the ground, when controlled by GSX.
That doesn't obviously mean GSX is the "cause". It simply means that airplane, used at that airport, has issue with ground physics when it's controlled by an external input. You can get easy proof of this, using a default airplane or the same airplane or another airport.
If it "was GSX", it should happen everywhere, with any airplane, and we would had the forum flooded by thousands of similar reports. Instead, it's just 2 users in 3+ years that GSX has been out. So no, it's not GSX.