Not a GSD - But I had my daughter's Beagle on one of those stupid retractable leashes - my sister and I took him outside to go potty. Somehow he manage to clothes line my sister right behind the knees and she nearly did a perfect flip. She was sore, but nothing broken.
I laughed so hard I ended up on the ground too.
Hondo Von Dopplet L Bauernhof "Hondo"- GSD
Lilie's Tug McGraw "Tug" - Golden Retriever
Maggie - Mini Dachshund (Rescue)
Lonestar Pivo - Texas Blue Lacy
Ashe - Barn Cat
Katie / APHA