Oh I get that, just the odds still have to be high, really high. Even with both planes looking, you'd think out of 5 people...
But then I'm a turkey in a small plane, helping look for traffic...
You'd think that many eyes would help, but most folks don't do the turkey thing as a passenger. I've spent I don't know how many hours(easily over 1,000) as a passenger in small fixed and rotary wings at work. Believe me, far too many people are just brain dead as passengers. Jaw jacking, sleeping, or playing on their phones. Everything except paying attention to WTF is going on around them. Baffles me.
Like you, I prefer to up my odds, and have my head on a swivel, especially when in obvious choke points/high traffic areas. I also want a head set, and be in direct comm with the pilot. Couldn't tell you how many times I've spotted traffic or some such, that the pilot had yet to see. I'm not the least bit shy to let a pilot know about something I don't like. My life is more important to me, than his/her feelings/ego.
Hunting season is a high risk time in the air. Lots of pilots that only/mostly fly in the fall, planes lacking in the latest comm/nav gear, flying low/not announcing themselves on the radio at small airfields, game watching instead of flying. You name it, lots of stupid [bleep] goes on this time of year. To be clear, I'm not saying that's the case here at all.
Jeff
