Dang man. Glad you are ok though......Could have been much worse.
Who might that be?
figured something like that would happen one day since you refuse to use the garage where the ground is flat, so instead of asking for permission/cleaning/organize the garage for your use, you rather use the 90 degree downhill driveway to work on the car. you lucky it didn't crush your ass but it was bond to happen some day and I'm glad it was just a WARNING.
I'm very very glad you ok dude