I feel like this crash could have been avoided. The plane didn’t seem out of control or suffering from any obvious malfunction. Pilot error?
He got it into a stall and then didn’t correct it. You can hear him or the instructor realizing what is happening with his “Down down down AHHHHHHHHHHHHHHHHHHHHHHHHHHHHHHH”. Putting the nose down and throttling up that close to the ground can go against your own nature.
nose-up in that situation is indeed a mistake. It can be trickery because of the camera, but RPMs on the functional engine seems to be decreasing.