The story told is: Hi, JD here in Canada, The hoist in question was not a hydrulic variety but a chain and screw type. The hoist was regularily inspected and was inspected and serviced a couple of months before the incedent. What happened was that the double nut safety device failed and the second safety device split and allowed one side of the hoist to fall. The car in question is my 1968 SS 396 4speed Camaro. It has since been repaired. One note is that to stay clear of the car while raising or lowering as we had removed the stands to lower the car when this transpired.
More here: Photo Gallery: Lift Safety and a Destroyed ’68 Camaro - ChevyHardcore
And Here: Cautionary tale: Lift failure - The Garage Journal Board