Something in this whole story is wrong. Most fighter Acft have a mode selection switch or "mode selector"...which would be selected normal....if rear initiated ejection the front would stay....I'd say the Rafale would have this
As explained in the report, the selector for the Rafale-B has two positions: SOLO and TWO.
In the TWO mode, if one seat's ejection is triggered, the other seat's ejection will occur in sequence,
In the SOLO mode, each seat triggers ejection individually.
The selector WAS definitely on the TWO mode in this event, so the pilot's seat should have been ejected after the passenger's seat. It didn't due to a fault that led to the command not being transmitted properly to the pilot's seat. (The fault was due to some part in the selector breaking after the explosion apparently due to a screw not being tightened properly.)
The question whether the selector should have been on SOLO or TWO for this particular flight doesn't seem really relevant IMO. TWO is probably the normal procedure for a flight with a passenger.
There isn't any way of DISABLING the ejection trigger on a given seat AFAIK, so that could not have been done - which would have prevented the incident here.
In retrospect, it could seem a good idea for flights with passengers who are not well trained, but I'm sure there would be contradicting arguments. Besides, allowing selectively disabling that would probably lead to many more potential accidents.
As I said earlier, note that this fault, by complete luck (if we can call it that), actually saved the plane - a mere ~70M euros. Had the sequence worked properly, the plane would have been lost. How ironic.