The Satmar Rebbe was never in a DP Camp, he was on the Kasner train, and while he spent some time in Belsen, the train took them to Swizterland eventually.
He made it to Palestine in 1945.
Its important not to make Halachas as you think a Rebbe might have acted from an anecdote that may not have happend
The story could be about a Rebbe whose name I forgot , he had gone to Japan during the War and the only food he could get was rice. He did not know how to cook the rice and waited 2 days learning torah until someone could cook the rice for him.