It has been almost 2 years that Dylan has shown NO inclination to run off. Until tonight...loser.
I had him out back playing with a soccer ball (my yard is not fenced) and Dylan was dragging a 10 foot lead. He was acting like he always does when we play together, very excited but also following the OB commands I was throwing into the mix.
And then....BAM he grew a wild hair and off he went. He went tearing around the house and was gone. When I came out front I saw my neighbors out with their two dogs (*phew* That could have been baaaad.) and they told me where Dylan had gone. Anyway, I was walking around outside calling Dylan over and over trying to stay calm and not freak out. But finally, THANK GOD!!!, I saw my neighbor walking Dylan (who is now pulling to get to me
) toward me.So what do I do? Dylan knows his recall and performs it well, until tonight. The only thing that has occurred to me is that maybe I need to work on Dylan's recall when he is not already in OB mode. I have done work with him on a long line with a prong and also treats for rewards. We started with a foundation of close recalls and then increased the distance. He has done recalls with just a prong and a tab on and does them often. I am definitely considering introducing the e-collar at this point (obviously under the guidance of our trainer). I am also thinking about deliberately setting Dylan up for failure once he is ready for it.
What are y'all's thoughts? Other methods I could try that I may have just missed somehow?
Thanks. And sorry for the novel.

Mistakes can always happen. I'm glad that it turned out ok and he is home safe.
When we train. I just make sure that it is hooked to me somewhere. When we go to the field and she runs with it she has plenty of length to get her zoomies out. 
God only knows what happened that night but if Dylan heard or smelled something and his hunt drive kicked in, that recall is generally going to go right out the window if you haven't proofed that situation before.
I never really thought about having an "emergency recall" before so thanks for sharing that.
I use COME for formal recalls, and HERE for informal in the yard, and WITH ME for sticking close while off leash on walks or such. For getting them back faster...I will sometimes add NOW!!!