Control your dog please!!

Who lets their dog pee on people??? We were in Letna Park today and the girls were playing with chalk and I was sitting on the grass watching. A black lab came over and played with Watson for a couple minutes then came over behind me. It was a good thing Jason was watching because the dog almost peed on me!! The owner is lucky it didn't because with Czech or not I would have yelled at her. Who allows that to happen?? I can understand if a dog doesn' tlisten perfectly to a command but come on! If your dog does that then he should never be off a heel when there a people sitting in the grass!