Was that Submission?

There have been a couple of signs this week that Ace will not always be a naughty boy. First, we had visitors on Saturday, and they wanted to see the horses. Ace was standing guard over the barn from the pipe corral, so we went to visit him first. I warned the visitors that he might bite, but to go ahead and pet him. They petted his face for about five minutes before he showed any signs of being nippy. Mostly, he was friendly and curious. So, that went remarkably well.

Today Ace looked like he really wanted to play. I got the longe whip and went into the arena with him. He raced around for 10 minutes with me not moving a muscle. In and out the door, around this way, back out, back in, around that way. Finally he had enough of me standing about in such a boorish manner, and he had to invite me to interact. He would "whoa" on his own, then sashay up to me like a dancer, mincing his steps, suspended 6 inches above the ground. If I made a move towards him, then he would leap in the air and rocket off again. "Nah na Nah na na... you ca-an't catch me". As his clock began to run down, I enforced "whoa stand" and walked up to him. I put my arm over his back as if I were mounted and pulled my hip up to his side, and stayed with him as he wiggled about and gave me the "hairy eyeball". If he reached to bite, I would tap the bridge of his nose with the butt of the longe whip "no bite". I did this several times on each side, waiting until he was standing quietly before stepping away from him and sending him back out on the circle.

After a few whoa sessions, and getting rapped on the snout for trying to bite, he began chewing, took a deep breath and dropped his head to his knees to study the ground. What's this? Submission?