Someone correct me if I'm wrong but I thought the captain thing was debunked. Apparently when you flow and they hold you back a few months you get a seniority number for a few months while he was still at Endeavor. I believe he was offered the flow and then didn't actually follow through in the end so he was "on the list" for 3 months but never physically on property. So he didn't fail out of training, he chose to stay.

That's how I understood the story from the Ex endeavor guys I've flown with recently