The crushing of a little finger was a minor high lifting jack injury.
I spent 15 days in hospital, lost an eye and had facial reconstruction involving metal plates to replace the eye socket.
The jack was dry of lubrication and one of the pins failed to lock in when lowering. The jack dropped to the next pin and as it did so the handle was forced up very violently striking me in the face. It was only due to the attendance of a doctor, an emergency nurse and a paramedic at the event that I survived.
There was nothing machanically wrong with the jack but the owner who knew better used it "just this once" whithout properly lubing it.
My advice to the owner of the "farm" jack is to cut it up throw it away and buy a Hi-Lift or JackAll . These two are well made the cheap replicas are not.
Before each use use lots of good spray lubricant such as Fluidfilm (NOT WD40 which is not a lubricant)
Yes I do still use my jacks but I'm damned caeful now.
John