This occurred to me several times back when walking the family dog Tillie (r.i.p.) and just did again as I saw some lady walking her dog on 42nd St.
Dogs don't pee where they think they're peeing. They sniff and sniff for that right spot to go, find it, and go. But the thing is that they stop walking when they find that magical plot of land that they find to be the perfect one for elimination. Correct me if I'm wrong, but it all comes out the other end on a spot they already sniffed and passed by while their head is still hovering above their chosen spot. This means they're taking a leak on a spot that's located a couple of steps before the spot they sniffed, so they aren't even going on that spot they chose in the first place.
If you're a dog and reading this, you're welcome for my bringing this to your attention, you dumbass. Keep walking just a few more steps once you find that spot and THEN go pee - chances are you'll be a lot closer than where you thought you've been peeing all these years.