Homsap - whats the axe to grind? If they're filming for broadcast then the operator would be mad to have not acquired the relevant CAA permission for dropping an article from an aircraft, and possibly low flying of sorts. One of which (for what you describe) would be the ability to hover on one engine, which the 355NP (the most powerful 355 variant), with a relatively light fuel load, and a handful of light kids should be capable of doing. The drop down with single engine hover performance would be minimal, far less than the height loss in a typical single engine fly away. In the order of 10-15ft, if that.
I would RATHER my kids jumped out of a twin engine helicopter with single engine hover performance, and a safety team/boat waiting by, than the frequented cliff jumps of Thailand from 20m dubious rocky outcrops, with rocks to clear, and no safety team. That said - I let them jump in Thailand, and jumped with them, and we all went home happy because it's a lot of fun, and sometimes we do things that we deem acceptable that others may not. Unless he made your kids jump which would be entirely different I say let them do so long as they're all consenting and aware of the risks. Some kids race motorcross, some ride horses, some ski/snowboard/skate/bmx. I'd suggest all the above are more likely to end in pain, and I'm sure their risk assessment would show that.