Centaurus,
RIP the poor guy. I guess he possibly couldn’t swim as well. Maybe this is why he was hesitant to get out of the car early.
The crowbar in the Spitfire door was actually to rupture the landing gear hydraulic lines. Basically the L/G emergency system was a CO2 bottle on the RHS of the cockpit. If you inadvertently activated this with the gear up the pressure meant that you could not move the landing gear lever (more correctly called the chassis lever) to the down position. This resulted in a number of wheels up landings. The solution in typical British fashion wasn’t to re-engineer the system but to provide the crow bar. If you inadvertently fired the CO2 bottle you could then rupture the up line going to the chassis control (the gear lever) and relieve the pressure and drop the gear.
The canopy jettison system was a knob above your head, a pretty simple and light weight system. Of course like everything it did fail occasionally.
Beez