Ended up parking in the alley next door and turning on the flashy light things (whose technical term escapes me for the moment), which allows me up to fifteen minutes of parking there.

I've never heard before anything to the effect that turning on one's flashers allows one legally to park up to fifteen minutes in locations in which one would otherwise not be permitted to park. That's okay, there's a lot of law type stuff of which I've never heard before. I was wondering, though, whether you are presenting this as legal canon or whether you are saying this jokingly in light of your having parked this way?