Yes, I would point to the springiness in the system. But that is a generalized proposition. I don't know anything about the specific construction of the mount.
But you cannot get around energy dissipation whether it is a pendulum or any other oscillating system. It has nothing to do with gravity or not.
Energy dissipation occurs even in space - agreed.
My issue has to do with the "decreasing amplitude" of each successive oscillation. In Gravity -- THIS is what energy dissipation would look like.
While in space (weightless), it would continue with SAME AMPLITUDE, but a decreasing SPEED.. it would simply "Slow down"... each time going to the SAME hinge constraint and bouncing off of it. Each bounce would reduce the energy, and as it rotates, the hinge itself applies some resistance... But in the end - it would randomly stop ANYWHERE along the path -- with the MOST LIKELY place to stop being just AFTER a bounce... As the bounces would be the thing that reduces energy the most (like a step function).
Instead, it hones in on the center position, reversing direction before hitting a hinge constraint. Therefore, some FORCE has to ACT ON IT to reverse direction. MLH says that this force is gravity.
So far, TD's best proposal is that it was the servo-motor running a reset-algorithm, and instead of just moving straight to "center/default position" it oscillates very quickly/suddenly, 9x before stopping.
I'm open to using whatever wording you like for this.