An aerodynamic experience

Of course all of our flights are aerodynamic experiences, but we can usually make some sense of what we experience. Here's one that was a mystery from the beginning, and I’m still surprised by when I think about it.

A couple of years ago, I was flying in the front seat of a Grob 103 (nose tow hook) with an instructor for a spring checkout. He wanted me to try a slack rope recovery method that was very different from normal (and later we agreed was not the right approach). When I did the maneuver, we had a spectacular rope break...I could see the rope break simultaneously at the tow plane end and the glider end and fall away. The instructor could hear the broken rope segment on our end making noise against the fuselage. We had plenty of height, so we let the tow plane land, and moved over the runway to drop our short length of rope so the tow ring, etc could be recovered easily.. When I pulled the tow release to drop the rope, a second or two later (don’t really know how long) I noticed something at the open canopy window to my left. There was a foot or less of rope flapping around just inside the cockpit, so I pulled on it, and the entire three feet or so of the broken rope segment with the tow ring on the end came in through the window.

That defied all my expectations. Why wasn’t the rope with ring immediately swept away? How did the end find its way to the window? I can start thinking about it with some aerodynamics principles, but I’d rather hear ideas from others.

Bret