Matt Damon on Jack Nicholson's improv skills “The Departed” (2006)

“He came out of the Roger Corman school. So he would always say, ‘I’m going to extend the scene. It won’t cost you anymore money because I’m not going to add any shots.’ A good example of that was there was an 1/8 of a page scene where it said ‘Costello executes a man in the marshes.’ And Jack went, ‘Okay, well here’s what I’m going to do. Have a man already dead. And have a woman whose kneeling, and I’m going to shoot her in the back of the head. And now I want Ray Winstone, my right hand man, in the scene next to me.’  And so he shoots her in the back of the head. Now you can end the scene there, as scripted. But if you leave the camera rolling, you hear him say, ‘Geez, she fell funny.’ Now you can end the scene there. But if you keep the camera rolling, Jack says, ‘Wait. I think I want to fuck her again.’ Now that’s a very sinister line.” More

Source: bravotv.com