As my players discuss some plans for next session by email, the limits of "town is safe" came up indirectly.
Here is how "safe" works.
North of Stericksburg are some run-down slums. All that's there are run down houses, tents of the truly poor and desperate, some criminals and exiles, and a few shops and stands that provide a modicum of a market for all of them.* And yes, the statue of Baron Sterick on his horse, arms raised holding his axe and sword.
These areas are not explicitly safe. Although I generally don't have encounters in these areas, trouble can follow you from the dungeons to these areas if you attempt to make a run for town.
Not accidentally, the North Gate, that leads to the Stone Bridge over the Silver River, is closed and guarded in the small hours of the night. You can leave town during these hours, potentially, but you can't easily get back in. During the day, the guards would be quick to seal off the North Gate if trouble is seen coming, without really caring if some delvers made it inside before they did.
Safe stops at the southern bank of the river. Don't raid the dungeon and flee to the slums to wait it out.
"Town is safe" works as a central conceit of the game only if you aren't trying to use it like base in a game of tag. Not that my players have done so, or even suggested doing so - but like I said, it came up indirectly and I figured I made as well explicitly explain my thinking.
* Obviously, this includes a stand that sells cursed frogurts that contain potassium benzoate.