I can't believe you rode with those injuries .
About the tires... don't you think the steel bridge had something to do with going down? There aren't many around here, but the 2 I have encountered (on the same ride) do not allow riders to ride over them. You have to walk. I find them to be quite dangerous. If a car drops some anti freeze, etc any liquid, they are going to be slippery as hell. I fell on one, walking.