The BBC did not in fact broadcast an appeal for Palestinian refugees in 1967 and incidentally nor did it broadcast one for Biafran victims the following year.
It seems that the Beeb has a long precedent for ignoring human suffering around the globe - although it's noticeable that the Palestinians keep getting the shitty end of the stick, but that if pressure is kept up long enough, the decision can be changed:
in 1982 ... the BBC turned down and then came under weeks of pressure and finally agreed to a DEC appeal for fighting in El Salvador and then later that year in the Lebanon war
This appears to be a rare event, however. Which only makes it more important to keep up the pressure on the BBC now. As Dr Franks says,
One can hardly make a parallel with Rwanda - since in 1994 it is unimaginable that anyone was concerned to argue the case for editorial balance on behalf of the Hutu militias! Similarly in the appeal for Kurdish victims in 1990 - there was no concern about balancing arguments in favour of a murdering Saddam Hussein.
So if there is a situation with a clear aggressor and total asymmetry between them and their victims the BBC usually changes it's mind or allows the appeal. Clearly then the Gaza appeal should have been broadcast (and given the miserableness of Mark Thompson's defence, I'm assuming he knows it too).
*Director of research, Centre for Journalism, University of Kent, it says.