Interesting! If you read the part about what Burstyn says regarding the initial meeting with Father Karras in the Washington park, it appears to answer some of the cigarette continuity issues at play. With only 52 seconds to shoot between the rush of airplane engines and the time of morning (starting at 4:00 a.m.), it is no wonder that the infamous cigarette episode took place.
I guess this also answers the question about the location of the park as far as what city, too. 🙂
Father Bowdern