Well, a little update:
Large peregrine (wouldn't swear it was the same one) was back at the west west haunt last night (May 31). I watched her/him for about 10 minutes at around 8:00 p.m.
He/she was behaving rather curiously in my opinion. She kept circling low over the building, kept landing (or trying to) on an odd part of the building only to immediately take off. He/She would fly almost up to her usually perch, yet not land there (almost as if she couldn't quite make it) and let herself fall away, only to do the same thing again. Maybe it was someone new looking Alice?