[ARCHIVE ANSWER]
The animal scents on the tire will cause the dog to "hang up" as he slowly investigates the scent with lots of breaths and interest. The K-9 will show all these signs without progressing with a scratch (aggressive alert) or sitting (passive alert) because K-9s are accustomed to animal distractions during training. When the handler recognizes the
interest without the scratch at the tire location, he will assume another dog peed on the tire or the auto hit an animal on the road and dismiss the interest for what it is, an animal scent.