He stopped trying to fish/eat because a shark snatched his first catch.
He didn't try to keep the LR cover to protect him from the sun.
He let 2 ships sneak up on him (too late for the flares) after waiting for several days just to get in the shipping lane.
Then he burned his liferaft down.
He no longer had any equipment to fish with. It was lost during the shark problem. I thought that was obvious.
I don't remember the LR cover sequence please remind me. I don't know what you mean by LR in any event.
Notice the challenge wasn't that every move he made was perfect from a monday morning quarter back perspective.
The challenge was to show something that happened in the movie that couldn't have happened. People that are tired, hungry and thirsty can make mistakes in fact I think you can count on them making mistakes.
I've already explained the burning down the raft. It may have been the most prudent course to give it his all and take a chance that a big stinky rubber fire would get some attention if he knew he wouldn't survive much longer anyway.
But since no one can come with anything that was impossible I'll extend the challenge to include seamanship choices.
He did a lot of things I would not have felt comfortable doing but none of those activities directly lead to worsening his situation.
What did he do wrong as a seaman, I'll bet I can defend everything he did.
I'm assuming the time frame was maybe the 60's when the radio he had was state of the art. I'm also assuming he had normal gear for his day for that kind of boat not anything cutting edge.
This one I'll probably regret as someone has to come up with something.