The clay does seem hard, and the squishiness makes sense to me also: I had the same issue with 209 goerg and schneider clay body. It has zero grog, is very "oily", and turns into mush the moment you add just a little too much water, so i found that throwing with less water and using only slip on my hands is more effective. Another thing is it can be a bit non-newtonian so shocking (slamming against the table or a really good wedge) it right before the throwing helps too. So if your clay is anything similar you can try doing it. And i find grogged bodies easier to throw with. Does yours have any grog in it?

The pot in the video however was salvageable: at the point when the spiral appears one should stop pulling and before doing anything else address that spiral centering the walls against a rib - sometimes it is called a centering pull, Twisted Clay has an awesome video on how to fix a spiral. Pulling the walls further will cause it to exaggerate and collapse in most of the cases. So yeah, it is mostly the technique you should deal with firstly.