Terrible story for sure. It must have been awful for his poor daughters. Still, I wonder about how this happens even when without a spotter. From reading the article it sounds like he just dropped the weight on to his chest and let go of it. Unless it slipped out of his hands I am not really sure how he couldnt get it off. I wonder if something else didnt happen to him to cause him to drop the weight.
I never use a spotter but I work out in a crowded gym, worst case scenario I embarrass myself. And I have had lifts where I got to the bottom and could not get it back up when I have either rolled the bar off of me or let the weights drop off the sides.