I am just now reading that the addition of four collapsible lifeboats was what went beyond requirements. Two of those boats were not "properly launched". Collapsible A was washed off the deck with a very few people aboard, and went into the water half submerged. Collapsible B had fallen upside down on the deck while being dismounted and subsequently abandoned, but it floated off (still inverted), and some crew were able to cling to it and survive.
Once "full", however, they had to shove their crewmates still in the water away to prevent it from capsizing.
That sentence is everything wrong with the world.