to me it sounds logical for the counter-sniper not to shoot first, it would have brought several legal problems on the table if the secret service killed someone first and asked questions second, there would definitely be lawsuits on the table against the secret service and the one who pulled the trigger.
I think the SS would have been protected from liability by killing a man with a rifle crawling on a roof towards a political leader. (At least here in Canada
intent plays a big deal.) On the other hand, now they do have a lawsuit (probably) for allowing that innocent civilian to be killed.
Heh, these kind of events are difficult to end up without having to deal with a lawsuit, aren't they?
if it was not a lawsuit from the family of the shooter, then I would not be surprised if the family of Donald Trump would bring a lawsuit on the table because of alledgely allowing an armed person to climb up to a roof near the him.
Though, I don't have much knowledge to how far secret service immunity goes and what they are allowed to do and not.
A reasonable think to do would have been to neutralize the threat by non-lethal means, but I guess that was not possible.