$ feet sounds like a normal 55 gallon job, the pic is likely an archive job, the MSM dont do reporting from the real outside world any more, he was 80 and probably shocked or stunned so to upsed the heavy but was too much in the short time, panic would have been an issue too, sad tale, I expect the elf and safety lot will inspect everyones but now??
It is conceivable I think. We had a water butt not disimilar to the one in the pic. If you got wedged in you would have areal hard time getting out. Especially an 80 year old.
Ours is very much like the one shown in the article, except due to some shifting, the top (which is very different from shown) rests askew on top. If his was anything like ours, I can see where falling on it would knock it off as it isn’t secure, and a person could fall right in. And you’d be wedged in there. Sad story.