In Hot Fuzz, they find a giant weapon's cache at this old man's house. I remember him saying something about he found him. Do we have any idea where they came from? If not, was this supposed to be a nod and a wink at some type of trope?
It is meant as a satire of other action films where people simply seem to have access to special force style weapon caches.
The joke ("Found 'em") makes you think about where on earth all of these guns and a sea mine could possibly have come from and how the old man could have obtained them.