You shouldn't let your dog pee on people.
Chris sees his dog approaching and sniffing other people at the park and thinks that the dog may be looking for somewhere to pee.
Chris wants his dog to relieve herself, so they can go home.
Chris calls his dog over to him and leads the dog to an appropriate place to relieve himself.
Chris ignores his dog and gazes at the scenery around him, waiting for the dog to be done with his business.
The dog pees in an out of the way area and Chris is able to get him back into the car to go home.
Chris doesn't see the dog lift his leg and begin peeing on another park visitor, which infuriates the visitor and causes a confrontation to occur.