So this is a particular genre of thread that seems to be popping up on BF constantly. Show some breach of etiquette (real or otherwise) by a cyclist, then make some vague complaint about how this makes us all look bad like there's someone out there keeping score..
Basically your complaint is he partially obstructed a sidewalk for a few minutes while he bought a slice of pizza? No idea why this is worth starting a thread about. People block a portion of the sidewalk all of the time, and it's clear people could get around the trailer. If you've ever ridden with one of those trailers, you'd know that figuring out where to lock it is a problem and that doesn't seem terribly unreasonable for a short stop..