i would have dug a hole so i could be at the right height rather than bend over to use the tools on it,, and he should have ran it faster and gotten a better finish
From his position and the position of his turning tool---I hope he has brass you know whats. If not, he was flirting with eternal, excruciating, agony.
I just cannot imagine anyone turning with HF turning tools on a piece that large, especially from his position.
At 150 rpm, I wouldn't be too worried about anything blowing up. Even on a 13" diameter piece, that's pretty slow. It makes my back hurt just looking at his position while turning, though.