Potty Training

So.. I just started potty training Thomas and he is doing so well these past  two weeks. He only wears a diaper at nap time and before bed. While the rest of the day he is a big boy and pees in the toliet-- completely accident-free! 

That is until today.. We were playing outside and I guess he did not want to stop for five minutes and go ALL the way in the house.. So he decided to open my car door, pull down his pants and pee on my carpet of my floor! Then he proceed to come and tell me he went to the bathroom in my car! 

So does this "incident" count as an accident, purposeful or clever?