Speaking of the Devil

I heard recently that Craig Mulcahy, principal trombonist of the Kennedy Center Opera Orchestra, won the second chair in the National Symphony.
Thinking of the Kennedy Center Opera brings back two memories: one good, one bad.

First the good:
Years age, I was hired as a freelancer to play some offstage brass licks during a production of Boito's Mephistopholes. Samuel Ramey sang the role of the devil. In one big scene, the devil has his big aria (his triumphant moment). Ramey leaps onto a table (shirtless) and belts out this incredibly resonant sound. Every night, the offstage brass guys would immediately stop chatting and simply listen to Ramey's incredible sound. Since the guy was shirtless, you could see that he was totally relaxed.
It was amazing to hear that much sound come from any human body with so little effort.
I'll never forget it!

Now the bad:
At some points during this opera, multiple brass choirs spread out through the hall play "trumpet calls" back and forth. Sometimes, two trumpets, far apart must perfectly match pure fifths and octaves. Here's the kicker: when we played, we could only hear ourselves, *not* the other ensemble!

Tell me this: how do you tune to someone you can't hear?

Of all the times I've seen trumpet players plop tuners on a stand during the gig (a pet peeve of mine) this was the only time it was really called for. They didn't do it, though.
Not a happy ending: things didn't sound too good and the pit orchestra players were annoyed with us.

This raises a vexing puzzle: one of the pit trumpet players kept telling us: "Remember, the pitch drops when you're farther away!"

Wait, think about that.

WARNING:
TECHNICAL DISCUSSION APPROACHING.
DO NOT READ THIS AND OPERATE HEAVY MACHINERY

I'm not talking about the doppler effect. I'm talking someone standing still 50 yards away from you. When they play a note into their tuner, will it be in tune on your tuner as well? I've heard many professional players insist it will be flat when it gets to you.
But think about it: a trumpet bell vibrates at 440 cycles per second and those little compressions of the air start traveling at the speed of sound towards you. If that trumpet player holds the note for a second, we've got 440 compressions flying through the air. You'll hear a note lasting for a second. If, in fact, they arrive at a frequency of 438 cycles per second, where did those other compressions go.
Hmmm...