Did this when i first started driving and the unit didn’t have a buzzer on the handbrake. Connected up and lukcily the yard light was in direct line of the catwalk, so when that dissapeared i was like… “uh?” looked down at the moving floor and wacked the read airline off faster then then you can say disestablishmentarianism 
Our units have always used palm couplings because we pull Italian trailers, i guess blighty needs to be different? 
But condolances to the drivers family, poor chap was only out there trying to earn a living with a bad day gone tradgic 