Read it again.....it was not a non voided slab. It was a 6" pour......but not under one post. My post was to try and give the guy advice he asked for, not to start an argument or give a litmus test for belief. Pretty simply, three guys (I was one) were pulling on a long prybar trying to move something on the car and the concrete under one post gave it up. When that happened, the weight shifted and pushed the opposite side post out of the foundation and that whole end of the lift hit the floor. We were glad it made lots of noise, because by the time the first post fell, we were out in the driveway. The second post had no void involved at all. He even had the original building inspector from Gray come out and he said the first post was mounter on top of an "air pocket" were his words. You could see it too. There was a lot of porous area where the post gave it up. Matt had the entire slab dug up and re-poured to 8" and by a different company.