I imagine that you weren't only pissing blood but that your piss was a dirty brown colour, like tea right?
If so then that's an extreme case of dehydration, you're kidney's were starting to shut down, basically you were dying... You probably should have spent at least the night in a hospital on a dip to hydrate and to be under surveillance in case your kidneys continued to deteriorate.
I'm not sure when this happened or how old you were at the time (honestly I'm not sure that it ever happened at all, not because I don't believe you per se, but you know this is an internet forum and all), but whoever your coaches were should have been at least disciplined, but more realistically fired, for totally failing in their duty of care, because for a case of dehydration (and probably heat exhaustion) to get that bad they would have had to ignore a lot of pretty obvious symptoms of distress, for example delirium... And if their was a team doctor (which there may or may not have been depending on how long ago this was) and the other first aid services present and they didn't send you to the hospital then they should have been in very big trouble.