FWIW, here's the scene from the revised script I found online, dated April 26 1971 and credited to Tidyman and Friedkin... I haven't had time to read the whole thing, but I'd bet both the actors and Roizman are right.... some scenes may have been more improvised than others. In Eric Sherman's DIRECTING THE FILM, Friedkin says it was the first day of shooting, and after 30 takes, the scene was still laying an egg. In the course of the sleepless night that followed, Friedkin had the inspiration to stage the scene outside the confines of the car and to let the actors improvise. The next day, two cameras, one take, and the scene was in the bag. INT. DOYLE'S CAR - DAY 3-shot of BLACK PUSHER sitting between DOYLE and RUSSO. DOYLE is at the wheel. BLACK PUSHER is sitting on his hands, wrists manacled behind him, his head down and dripping blood onto the jacket and the canary-yellow turtleneck. All three are breathing hard. DOYLE What's your name, asshole? BLACK PUSHER Fuck you, Santa Claus! DOYLE hits him across the face.  4. RUSSO Your name is Willie Craven. BLACK PUSHER doesn't look up. DOYLE Who's your connection, Willie? What's his name? No response. RUSSO Who killed the old Jew in the laundromat? BLACK PUSHER's brow furrows, looks up just a little. BLACK PUSHER I don't... DOYLE Ever pick your feet in Poughkeepsie? BLACK PUSHER What? DOYLE Did you ever pick your feet in Poughkeepsie? BLACK PUSHER I don't know what you're talkin' about. DOYLE Were you ever in Poughkeepsie? BLACK PUSHER No... yeah... DOYLE Did you ever sit on the edge of the bed, take off your socks and stick your fingers between your toes? BLACK PUSHER Man, I'm clean. DOYLE You made three sales to your roaches back there. We had to chase you through all this shit and you tell me you're clean?  5. RUSSO Who stuck up the laundromat? DOYLE How about that time you were picking your feet in Poughkeepsie? The BLACK PUSHER'S eyes go to RUSSO in panic, looking for relief from the pressure of the inquisition. RUSSO (in pain) You better give me the guy who got the old Jew or you better give me something or you're just a memory in this town. BLACK PUSHER That's a lot o' shit. I didn't do nothin'. The BLACK PUSHER's eyes are on DOYLE, frozen in confusion and fear. DOYLE You put a shiv in my partner. Know what that means? All winter I gotta listen to him gripe about his bowling scores. Now I'm gonna bust your ass for those three bags - then I'm gonna nail you for pickin' your feet in Poughkeepsie.