Zalt,
The work started on the revision and the change of status from guidance to rule about 2001 - manufacturers were on the committee which had oversight of the work.
Rather more complicated than it appears. The changeover to the glass cockpit required an interface and/or a bus that could make the parameters available.
Retrofitting, once the problem was brought to light, would have been an expensive proposition for what is to be a discontinued range and, where, for other than the JAA (the USA for example) no FDR was required (and if fitted would not have to meet the latest ICAO/JAR requirements).
Better then that the cameras provided recording of the flight instrument displays - particularly as they would also be of a type that could meet the (relatively new) ED112 requirements. A good solution all round.
Yes, the TCH holder took their eye off the ball - mostly because they lost their regulatory expert (committee member) to 'health issues'. Once the discrepancy had come to light (and it is not clear that there was any 'agenda') all had to work together to provide a solution in the shortest time possible. This involved the sourcing of relatively new equipment and trialling it to ensure it met the ED112 Standards.
All who have been involved in these types of issues know that it is better to all work to a common solution than to dig their heels in and ground aircraft.
Toothles tigers - probably not in this case.
Jim