Just to clarify, are you asking so you can start containing the cat at night so that they only miss the box in an easy to clean room? Because trying to correct behavior only works if it’s immediately after they poop on the floor, if any time passes they won’t make the correct association.
How many cats do you have?
How many litter boxes do you have?
Is the litter mat kept clean and washed regularly (and not only because it was pooped on)?
There should ideally be at least 1 litter box per cat, plus 1 more to reduce the chance of stress pooping.
As others have mentioned, cats will also sometimes avoid going in a box if they perceive problems with it, eg too much/too little litter, box hasn’t been scooped recently enough, etc.
Fog dampens sound more than you may think, it’s very possible he heard absolutely nothing, and with it being so thick no one would be able to tell he was still there.