Nah… Fatherb is right. I'm sure that's what Friedkin thought, as well. When it comes to Friedkin &The Exorcist there's no such thing as just a coincidence.
Oh yeah I just remembered Friedkin saying in the 25th anniversary DVD commentary that he didn't like one of the 'extras' clothes color, it was while filming the exterior scene with Ellen and Jason Miller. He had to stop shooting the scene and ask the guy to go away or something like that. I'm pretty sure he said that.