dragartist,
if your comment refers to the Loadmasters following the load out of the a/c then I at least used to do it partly out of relief when I saw that all was well and partly to provide an eyewitness account if all was not well ! Especially on trials. Cameras did not always catch all the action. Then on the heavy drop to retrieve the transfer release cable.
Yes on a Volant Rodeo exercise Dougie M put the platform bang on the DZ marker. This did indeed result in the vehicle being a write off. Doug may still have the pic.
I do not know about the USAF rules for the loadmasters but in the RAF in my time on airdrops before any ramp or door was opened you had to be wearing your safety harness and have it hooked up to an anchor cable. This was the SOP, and was an instant fail on any air check if you did not.
The comment by Mogwi is IMHO correct. It is how the fall of stores was reported to the a/c crew based on the clock (and an estimate of the distance from the DZ letter) with twelve o'clock at the farend of the Dz and six o'clock at the start. So in the clip shown the platform is off the far end of the DZ at twelve o'clock.
Best wishes.
Bill