It might have been human operated, but it also might have just been copying its training data.
A robot that properly supports being teleoperated wouldn't immediately fall over the moment someone deactivates a headset. Falling over is almost the worst thing a robot can do, you would trash a lot of prototypes and expensive lab equipment that way if they fell over every time an operator needed the toilet or to speak to someone. If you had such a bug that would be the very first thing you would fix. And it's not like making robots stay still whilst standing is a hard problem these days - there's no reason removing a headset should cause the robot to immediately deactivate.
You'd also have to hypothesize about why the supposed Tesla teleoperator takes the headset off with people in front of him/her during a public demonstration, despite knowing that this would cause the robot to die on camera and for them to immediately get fired.
I think it's just as plausible that the underlying VLA model is trained using teleoperation data generated by headset wearers, and just like LLMs it has some notion of a "stop token" intended for cases where it completed its mission. We've all seen LLMs try a few times to solve a problem, give up and declare victory even though it obviously didn't succeed. Presumably they learned that behavior from humans somewhere along the line. If VLA models have a similar issue then we would expect to see cases where it gets frustrated or mistakes failure for success, copies the "I am done with my mission" motion it saw from its trainers and then issues a stop token, meaning it stops sending signals to the motors and as a consequence immediately falls over.
This would be expected for Tesla given that they've always been all-in on purely neural end-to-end operation. It would be most un-Tesla-like for there to be lots of hand crafted logic in these things. And as VLA models are pretty new, and partly based on LLM backbones, we would expect robotic VLA models to have the same flaws as LLMs do.