Alan, as the customer you would class as the high ranking observer so its not surprising you saw the rules in action.
We watched from Boscombe the mass drop on Everleigh that the Queen was observing from Sidbury hill where two MSP whistled in. Apparently the Brigadier turned to her and said "Sorry Mam that's not meant to happen". The Queen's reply showed that she knows Butler's laws as she said "That's all right, it always happens when I watch."
Wet Through was ideal for water drops, the proximity of the runway to the DZ meant that you could brief and then sit and wait for a break in the weather and then launch , drop and get back on the ground all in 20 minutes before the weather closed in again.
As for cows, I have photos of the one JATE killed with a platform that missed the DZ.