True story... A friend of mine (Dragon Dronet) worked on that film. He tells a story about how Danny DeVito got stuck on the device that made his umbrella helicopter lift while very high up, and in costume. Instead of cursing and shouting to be let down as one would expect an actor would do, he told jokes to lighten the mood. I don't know if Danny knew how afraid the crew was that the device would fail and cause him to fall.