I agree to see him cheering so quickly after quitting the race was alittle distrubing. He's a tremendous talent and I wouldn't suggest running without a shoe as a couple posters stated; however, quitting should have been the last thing on his mind as a competitor.
the 2 options he failed to consider once his shoe came off:
1.) attempt to put shoe back on quickly as possible hopefully ONLY losing 2-3 seconds at the most and continue
2.) attempt to put shoe back on as quickly as possible; however, if it takes more than 5 seconds then consider stopping
The pace was so slow he shouldn't have had a problem regainging the group; however, German didn't know how slow the pace would actually go out. It seems German didn't think he was in shape to win the race and once the shoe came off apparently he felt his chance at simply competing ended as well.