My mother used to point out the patched hole in the ceiling at one of her labs where a grad student loaded up an ultracentrifuge without a counterweight. I guess it was easier to do in the '60s.

You get to 100,000 g and then you're talking about balancing to the hundredth of a gram. Obviously it's all relative, and here I'm sure they've designed to the known forces and expected changes in angular momentum, but I just don't see how you don't break the rotor arm here.

LOL they have done no such fucking thing.

What cross-section shall we pick for the arm? How 'bout 2m? 10,000g x 11,200 kg x 9.81 = 1.09e12 n /2 = 500GPa. Know of anything with a tensile strength of 500GPa? 4130 chrome moly is at 0.435 GPa so normie shit is straight out. Kevlar 49 yarn is at 0.235 GPa (with 3% elongation - that's 14cm on this rig). Carbon nanotubes? 270-950 GPa! Hey we have a solution! Except they don't exist for lengths longer than a stack of dimes and we haven't exactly broached the subject of our release mechanism yet.

If a cursory examination of the Newtonian mechanics at hand invokes unobtanium, we can safely argue that absolutely no analysis such as this has been shown to investors or shareholders. Somebody on the company either has a rich daddy or serious kompramat over Airbus Ventures, Kleiner Perkins or both.

Maybe a sliding counterweight on the opposite arm that can be brought to the center immediately upon release?

"Effective weight equal to an ocean liner" plus "brought to the center immediately" is a delightfully humorous concept. Conservation of angular momentum dictates that to take the counterweight force to zero by pulling it towards the center, velocity must go to infinity which, I mean, given everything else going on, why not? So now your gear motor must do more than sling a pair of ocean liners around at 450 RPM, it must also be capable of accelerating to light speed instantaneously.

Or I dunno I guess you could do that and then hit your magnetic brakes in a futile attempt to absorb that energy. So what took you an hour to pump in, you now need to pump half of it back out as close to instantaneously as possible. Which I'm not going to do the math on but I'll bet it's in the neighborhood of having your facility struck by lightning.