Why do you think he didnt leave the yard?

Well i have a toy poodle and today i left the house unknowingly leaving the door open. Well i came Up the street and i see rudy sitting in the yard so i called him and he refused to leave the yard. Like he Would walk to the edges of the driveway but wouldn't leave the yard until i got to the neighbors driveway and it made me wonder i mean hes a good dog but even so im surprised he got the chance to run and didn't unlike my other dog.