I guess what I'm now wondering is whether or not something requires a certain drag coefficient to, upon achieving trans-sonic speeds, create a shock wave in the air.

Obviously they probably didn't produce a shock wave at absurdly high altitudes, but were also probably falling at trans-sonic speeds.

What I was trying to mull over was for how long and at which point could something like that achieve enough drag to presumably both travel at trans-sonic speeds AND produce an audible shock wave as per an aircraft achieving the same speeds.

But that is also why I put in the disclaimer about high aerodynamic capability, because obviously the terminal velocity would be enough to surpass that pretty easily. I didn't know it would be Mach-3-easy, though.

Edit: That is pretty awesome though - traveling that fast would mean you wouldn't hear it coming...

Does it even produce a shockwave when there's nobody to hear it?

Not if they're already dead.