I was in this race too and it isn't a race that I will soon forget.
Turning and doing my best to dodge runners, trees and spectators was quite the adrenalin rush. I was able to get back into very similar position to where I was when I turned around with in about a minute because The runners at the back of the pack went relatively slowly out of confusion and respect for the front runners. It seemed kind of like the Tour de France where the peloton waits when one of the favorites goes down.
When it was all sorted out runners the race could have finished and the results wouldn't have differed much compared to if there weren't ever a mishap at all. That said, anyone who was remotely close to making nationals would have filed a protest and possibly taken the backdoor to nationals. I understand why the race had to be rerun.
As people have previously mentioned we could have run a 6k or an 8k. In my opinion neither of these options were valid because a 6k would have been much quicker and almost would have required a different skill set than a 10k. An 8k would have been difficult as well because the course was completely set up for a 10k. It would have been hard to teach the runners a new course in 2 hours or whatever.
I also get the impression that the NCAA required us to run a 10k so we did.
In my opinion the people that bit the dust in the second race were those that went out too fast in the second race. The heat and the 3 1/2 miles already in our legs made the second race completely unforgiving. I don't think that the first race, no matter how you ran it, affected the second race differently for different people.
I think that the way things were done were as fair as could be given the situation. I also feel that UCSD did a great job running the meet aside from the one giant glaring error.
There is no way of knowing how much the results would have differed had the race been run without a hitch. I think that for the most part the same people would have qualified to nationals.