Hi guys !
If that info may help you, the ignition sensor failure shutting the engine was triggered by the revmatching in my case.
Procedure for replicating the fault :
Ride on 3rd gear, fully pull the clutch AND revmatch while downshifting to 2nd.
Considering this procedure, the engine shut down every single time at the exact moment I rotated the gaz-handle, WHILE the clutch was pulled, so just half a second BEFORE I actually downshifted.
Hoping this may help you. ~