I think trying to keep 500ft causes problems ... I would rather be 300 ft with good viz , going slow , rather than 500ft half in it ... Regardless of what the book says !!
Or alternatively a pilot could have altered his/her plan and landed earlier. Decided not to get progressively lower and slower before it's too late.
Going close enough to touch the clouds is what's killing people
(be they ppl,cpl,atpl, civvy or mil - you get all sorts (good, bad, indifferent, reckless etc etc in all 'camps')