around 11 minutes the helicopter approaching the test facility is a Eurocopter/Airbus A-star AS350/H125 with a 3 bladed main rotor, but the sound heard is that of a 2 bladed main rotor (such as a Bell UH1 or 206).
When the General is looking at the name's of the five people to be executed, the list shows only prefixes and last names, thus it would take a considerable amount of time to get the right persons. It is unknown how they managed to get the correct five people in what appears to be under an hour.