I don't think many are claiming that Hopkins is gonna knock Calzaghe out.....certainly not with one punch anyway.
I didn't take a look at the video but I suppose those must be around round number 7. Calzaghe took those right hands but kept his chin down and absorbed... The problem is when he throws the right lead and falls inside to connect with the left - I guess there's a little hairline second where Hopkins' sneaky right hand can get right in the middle like happened with Kabary Salem (4th round). I don't think that Hopkins right hook is heavier than those shots Reid and Mitchell landed on him.