If you call the number,
“Hello, this is Sheriff Jackmannii, I was visiting my bedridden grandmother and noticed this note on her door, what’s this all about now?”
The correct poll answer turns out to be 1) contact local law enforcement.
According to Deputy Hoofsnrgle, there was a pickup rollover accident just down the road from us early yesterday morning, in which a neighbor’s cow pasture fence was damaged. Apparently no sirens were used by responding vehicles (weird in our experience) or we didn’t hear them, and the accident must have been cleared up in record time.
So our disgruntled-looking visitors evidently were in the accident and probably wanted to discuss fixing the fence (which isn’t ours, so no sweat as far as we’re concerned).
Thus we are relieved, except now there’s the worry that some cows might’ve gotten loose and/or been harmed. 
Ha!
(neighborhood in St Martin where the bovines roam and return to the barn late afternoon)
Are you the house closest to the accident?
Interesting. Also an unfortunate comment on current society that someone looking to do the right thing (discuss taking responsibility for and making right property damage) is viewed as a possible threat simply because they went to the wrong door and communicated their intentions poorly.
At what time in history have two scowly young men in an unexpected isolated context with unclear intentions not been potentially threatening?
And hung out for at least 8 minutes.