Ignition switches - safety

[Amie]

Discussion with a friend on the runaway engine subject. He put forward another even more bizarre scenario that he says happened to him. He owns a fordson dexta tractor (3 cylinder diesel) one day he says he almost stalled the engine and it started to run backwards! He says that the injector pump works with the engine running either way, but there is no control of the air entering the exhaust, though the engine stop (cable) fortunately does still work, didn't seriously damage the engine it just needed a new head gasket which failed between the oil and water galleries.

Thanks,
Amie