I never ejected from a Canberra but twice had the canopy jettison circuit fire - luckily both on the ground. Both incidents were finger trouble I hasten to add.
Interesting that the early T4s did not have bang seats for the pilots. The thread reminded me of the rather Heath Robinson arrangement of having to swing the right hand pilots seat forward so that I could climb into the back hole that was the bak of the Canberra trainer, and then have the seat swung back and latched into position.