Missing dialogue? (spoilers!)

I saw this remarkable film when it first came out--43 years ago!--and I still remember its power.

I saw it in a theatre in Durham, North Carolina. Durham was at the time a combination of a factory town (tobacco) and a college town (Duke University), and this was after the Civil Rights Act, so there was little overt public discrimination, but at the time (maybe still, I don't know, I haven't been back in decades), it still had many of the attitudes of the Old South.

So, I'm watching and enjoying it, but just at the final confrontation between Sonny Boy (Yaphet Kotto, a face new to me at the time, and a young giant) and the bad-guy racist who has been tormenting him, just before the bad guy becomes an intimate part of agriculture, the sound cut off and there was an announcement about some trivial matter--a car in the parking lot with its lights on, or something.

I've always wondered: Does either of the guys in that scene say something that the management of the theatre thought might offend the audience, and thus felt compelled to cover up? I suppose that I could have stayed for a second showing to see if there was an interruption at the same point of the film, but I didn't think of it at the time.

So: can anyone who has seen this film lately remember just what the dialogue was at this point? Many thanks.