I still find this tip bizarre.
It is possible that if someone murdered Steven, he had a slip of the mouth and someone reported it, but you would think that lead would be given to police and not the PI. The purported perp is not likely to call in a tip.
I suppose it is possible that someone knew Steven was suicidal and finally decided to open up. I have not seriously considered suicide as the choice of location is just baffling, when he could have jumped off many a roadway in the mountainous west. Why drive to SCA then walk to a field near an airport? Way too much work for someone checking out.
It is perhaps more likely that something was found on his hard drive that connected Steven to the airport. That would be a 180 from the public comments that nothing explained what he was doing in SCA that day.