Derek Boogaard example of athletic pain management gone terribly wrong

It was over a year ago now that Derek Boogaard passed away due to a drug overdose. Recently there was an interview with a pain management doctor on NPR about that state of narcotics being used for pain management in professional sports. It's interesting to note that Boogaard had been prescribed over 100 different medications in the three years leading up to his death. That's an insane amount of medicine for one person to be taking - I just don't understand how that happens. The doctor in the article blames it on the fact that there's a rotating staff of doctors that work between the games. But he also mentions that they do keep a thorough electronic record of the patient's history that they keep with them at all games. So how exactly do you NOT know what another doctor prescribed to an athlete two or ten games ago? This is a whole new piece of sports medicine that we're just starting to see. I'm interested to find out what else comes out on this, especially with the Olympics coming up.