Not exactly on point but last week I went on a ride with a guy I'd never rode with previously. About a mile short of our 34 mile ride I noticed he wasn't behind me any longer so I backtracked and found him lying on the path next to his bike. He was suffering from leg cramps, after a 10 minute break we finished.

4 riders (about 50%) slowed to asked if we needed any help or if he was in trouble. Pretty cool if I may say so. Bicycle riders rock!