Snow threw some haymakers at the Manchester United legend, calling his handling of the media "thin-skinned" and his leadership style "Stalinist."
He also asks him how he can support the Glazer family that owns Manchester United when he's politically left-leaning and they're "rampant capitalists."
It's remarkable stuff (full video below).
Here's the exchange after Sir Alex said he sometimes had falling outs with star players as a result of trying to maintain control:
Sir Alex: "Manchester United cannot afford for players to run the football club. It wouldn't be Manchester United. And I've said that time and time again to directors over the years."
Snow: "So control is all?"
Sir Alex: "It's not all, but it's really, really important. In terms of, if you want to stay in a job, you need to have control."
Snow: "Sounds a bit Stalinist."
Sir Alex: "Oh Jesus God..."
Snow went on to grill Sir Alex about why he banned the BBC from his press conferences for seven years after they did a documentary about his son.
He called Sir Alex "thin-skinned" and said, "I wonder whether your handling of the media didn't suggest you were weak. Weak in the sense that you couldn't take the rough with the smooth. So you banned a lot of people. You loved to chuck people out of your press conferences, 'You're banned. Ban that man.'"
Sir Alex gets a little salty at the 6:15 mark, saying, "You're wrong there. Get your facts straight," after Snow claims he once called the owners of United "rampant capitalists."
It's a long interview, but the entire thing is worth watching: