All safety demonstrations should be relevant to aircraft type. If the demonstration says that there are 10 exits, then there should be 10 exits.
If the demonstration says that you tie the tape on the life jacket in a double knott, then you should tie it and not click "tabs" like you do on the more modern Hoover life jackets.
I would suggest you contact BA giving them details of your flight (date, flight number) so that they can check if you are correct and load the correct demonstration onto the aircraft.