So, the dog is barking at the front door. When he moves, there is this poopy schmear all over the floor beneath one of his paws.

I just had him outside for a walk. Prior to barking at the front door, he walked in through the living room (carpeted), over the kitchen floor to get drink of water, and then back through the living room (carpeted).

If he tracked the turd in from the walk, how did it not end up on the carpet or the kitchen floor? He didn't poop in the house and track it - he was in my line of sight the entire time.

How did the poop end up by the front door? HOW???

I did end up cleaning both the floor by the front door and one hind (poopy) paw.