I've seen several explanations as to why there was a second trial that year and one of them was that in June there was a lot of suspicion that Ryun wasn't recovered enough to be sure he'd make the team in either the 800 or the 1500 at the LA trial. But once officials got around to acknowledging that altitude was going to be real factor in many events it made sense to have a trial meet at the same altitude to see who dealt with it best and worst. And as no one really knew specifically which events would be affected and how, remember there were events in which there was speculation that altitude would enhance performances, I think you needed to go ahead and do the whole meet at altitude. Looking back, I don't see any athletically based reason for holding the LA Trial.