Here is a website to get all the FAA info you could ever want.Not to be a spoil sport, but I do believe it is illegal to drop anything from a drone as per the FAA. Now I know this wasn't explosives like ISIS, but to the FAA anything being dropped is a no-no. And the risk of having a parachute foul a prop should have been immediately obvious.
Well, at least someone had fun...
Brian
eCFR — Code of Federal Regulations
You'll want
Title 14
Aeronautics and Space
It is not illegal to drop stuff from any type of aircraft, manned or unmanned.
As per CFR Title 14, vol. 2 ch. 1, part 107.23:
§107.23 Hazardous operation.
No person may:
(a) Operate a small unmanned aircraft system in a careless or reckless manner so as to endanger the life or property of another; or
(b) Allow an object to be dropped from a small unmanned aircraft in a manner that creates an undue hazard to persons or property.
I'm pretty sure that 2oz. Army man wasn't a hazard to anyone.
For manned aircraft you'll want to peruse part 91.15, which says basically the same thing.
§91.15 Dropping objects.
No pilot in command of a civil aircraft may allow any object to be dropped from that aircraft in flight that creates a hazard to persons or property. However, this section does not prohibit the dropping of any object if reasonable precautions are taken to avoid injury or damage to persons or property.