I think it should be pointed out here that nobody is questioning the decisions made in this particular accident towards the people trying to save this guy, you guys did what you thought was right and that is all that counts. There are many people who just can't handle situations like this but you guys did all you could and I'm sure everyone is grateful for that. Having been faced with a similar situation myself I know how intense it can get and not knowing what might happen next. In my friends accident, which was similar in that it was a huge fall, while he never went into cardiac arrest, we were faced with the problem of possibly having to perform CPR on someone who likely had spinal injuries if he did go into arrest, as well as moving someone with those injuries. Luckily two of us had significant rescue and first aid experience and we were aided by two people from this board who I will forever be in debt to.
For the people who were there, I would suggest seeking out some people who have been through all of this and can offer you some support. Witnessing something like this is VERY troubling, as well as humbling, and it's not fair to yourself to let these thoughts fester in your mind any longer then they should.