This might be a stretch, but from one that has perp walked people before, she (whoever "she" is) looks like they lost their footing. Her arms are in a position of someone being shackled. That would explain why her hands were behind her back. When you grab someone's restrained arm move them, the tendency is for the elbows to come up and out. That is what appears to be happening. However, the strange part is when her toes appear to catch on the curb, her arms break free. So my question is why the subterfuge, if that is indeed what it was? Not much makes sense in that video, unless you surmise that it was accidental.

The other theory is she was sedated, which is why they unceremoniously threw her in like a "side of beef". I don't see that one. What ever is the cause, she looked different when spotted later coming from her daughter's apartment.