Rabbi Dr. Tendler claims rabis don't have background to understand brain-stem death

Unfortunately a gross misrepresentation of the issues. It doesn't require a PhD in biology. He said the following:

JPost

“We underestimate the effort needed to understand the advances in biomedicine, people who are trained – doctors, etc. – have trouble keeping up with the field,” Tendler told The Jerusalem Post at the end of the conference. “Our rabbis enter the field at its most advanced stage, without the background necessary to understand it.

“The idea that greatness in Torah is adequate to make up with this deficit in education, is erroneous. Lo bashamaim hi – the Torah is down on the earth. Therefore, Rabbi Moshe Feinstein waited two years before he could answer the question [on whether brain-stem death qualifies as death],” Tendler said of his late father-in-law, the supreme rabbinic authority for Orthodox Jewry of North America and one of the greatest halachic adjudicators of the generation.[...]