They'll definitely defend themselves if you corner them, but if you leave it alone, they're not aggressive. Since it didn't find shelter or anything to eat, it'll leave. Vaseline on the railings is a good way to keep them from climbing back up, it's how I keep them out of my bird feeders.
Drowning a full grown GSD? Ahem .... (but +1 that a 'coon and a Corgi would be pretty evenly matched - still, it's not like this is the only raccoon in the world, so either your neighbor is going to keep their dogs in at night or they aren't ...)
Speed comes from what you put behind you. - Judi Ketteler