Just to keep us on course for the original topic, that of fleet age, I would point out that BZHC is actually the newest unit in the BA 767 fleet, dating from 1998, whereas the oldest dates from 1990. Which just shows once again that age has nothing really to do with it.
If a passenger believes that he/she has not received a satisfactory safety briefing, as required, their first stop should be the CAA.
I hope TS that this is not the case, but that the passenger's first stop should be to speak with the CC and point out that they have been unable to receive the safety briefing. There must be an SOP for what the CC then have to do in this situation, surely ? I would presume it then has to be repeated manually.