When you wanted to let him in and he didn't want to, so you left him out for awhile, you trained him it's ok not to come when called. I'd try the treat route suggested. Even if it takes him a long time to come to you, be sure and give him a treat, but only when he comes to you.
Is there something at the door that bothers him? Brooke wil only come in if there is a mat at the door and she always comes when called. One time there was a skunk outside and while she stared at it, ears up, she still came in when called, so she's not afraid to come in the house as long as there is a mat. the skunk situation proved it. Could there be any reason that would prevent him from wanting to come in, other than really enjoying his time outside?