That guy is less than 3 feet off of the ground, he could have picked some FOD up in his engine, it would have stalled, and then BOOM! Not alot of room for error. Not to mention he could have sucked one of the people into the intake........
It's not a helicopter, destroying the engine does not make the plane crash, it just makes it's flight a lot shorter.
I'm not saying it's not risky but if you know what your doing it can be done. And as I said before it seems that the people were expecting him, if they agreed to be there (they were not tied up so they agreed) than you can't blame the pilot for what ever happens to them. They knew it was risky, they took the risk, nothing happened, they went home happy.