I found this one while I was trying to trap a boar.
The story goes something like this *flashback*.
So, I have one part left to trap the boar, I click the wrong tile by mistake and click away from it before the hearthling sets up the building sign. As he approaches the tile on which I clicked by mistake, he doesn't have that little *tup* sound when putting up the sign nor the cooldown before he can walk again, he just puts the sign and quickly goes where I clicked before... The sign stayed there. I tried it once again and it actually worked. You have to temper the intervals, though.