For my (England's) part, it was just stupidity. I didn't consider the retreat from Munich to Kiel. There was a lot going on that turn, but it was foolish to overlook that retreat.
I only really have two other points on this game:
1) Once I was facing the Sealion, I had written my chances off. Once I realized I might survive it I decided to play more aggressively than usual.
2) Given that perspective, I was pushing towards a two-way draw even though Turkey was outpacing me. The hope was that Austria would fully focus on the Turk and I might be able to nip my way to 18. Normally I would have tried harder (and earlier) to rally the troops against a common enemy, but I felt like I was playing with house money at that point and went a bit more risky than I normally do. In retrospect, I would have only been marginally happier with a four-way draw than a loss, so I'm not too bummed about this result.