He doesn't need to mention it in the disclaimer because it's very obvious to anyone watching the show what he means by that.. I doubt that any viewer finds a problem about some assistants helping Derren to acheive the effects, especially when it's done in such an obvious way. After all, this is part of the magic world and there's no reason to put a disclaimer about this issue. Just common sense.
And I believe this is one of the few effects where he uses assistants like that.. I'll let you know if I remember anything else.
And I believe this is one of the few effects where he uses assistants like that.. I'll let you know if I remember anything else.