If you read the rest of the tweet by Arnaud, you’ll learn that Nazis later abandoned the practice of rescuing survivors of sinking enemy ships, and it was because Americans are worse war criminals than Nazis:

The history of this is actually interesting: the Nazis rescued survivors all the way until the so-called Laconia Incident in 1942 (en.wikipedia.org/wiki/Laconia_incident).

The Laconia was a British troopship sunk by U-156, a German U-boat, off the West African coast. Right after the sinking, the Nazis immediately began rescuing over 400 survivors, broadcasting - as was common practice - in plain English their position on open radio channels to all Allied powers nearby, so they wouldn’t get attacked during the rescue.

That’s when a US B-24 “Liberator” bomber attacked the submarine anyway, even though all the rescued survivors were on its foredeck. The B-24 killed dozens of Laconia’s survivors with bombs and strafing attacks, forcing U-156 to cast into the sea the remaining survivors that she had rescued and crash dive to avoid being destroyed.

The American B-24 pilots mistakenly reported they had sunk U-156, and were awarded medals for bravery…

This event completely changed Nazi policy on this matter: Karl Dönitz, commander of the U-boat fleet, issued the “Laconiarefehl” - the Laconia Order - forbidding U-boats from rescuing survivors, because the risk to the submarine was now too high.

In other words, the Americans during WW2 essentially forced the Nazis to abandon survivors - from the allied side (!) - at sea.

Dönitz at least had an excuse.