Hmm, banging on the FD door? Bonkers! Still, there are many nervous flyers out there. That doesn't however warrant behaving like a prat. If the pax could see it then the cabin crew would have been able to. If it was then indeed a serious risk, the cabin crew would have informed the flight deck. Those passengers actually endangered their own lives by standing up. Imagine what they would look like had the pilots rejected the t/o!
BEFORE you start telling me this and that about Kegworth etc, we have come a long way since then. Given the circumstances it was a bad decision to leave their seats.