All of the weight of the vehicle is on the jack... When you release it (after lifting it), the weight of the vehicle will want to SNAP that handle back. Keeping you hands, fingers or head between the handle and the jack will take 'um off..
Another things... Keep your old sissor jack. Somewhere, somehow it will become useful. With couple of wood blocks or flat stones, it could lift the Jeep from the pumpkin. I've have friends that had such an articulating suspension that the High Lift jack had to almost be at the top before it lifted the tire. He had to strap the axle to the frame to get that tire to lift.
Congratulations on your jack. It could be used as a come-a-long if really needed.