in the ceremony awarding a medal of freedom (posthumously) referred to the Nazi death camps as "Polish Death Camps"

"Poles Demand Obama Apology For “Polish Death Camps” Comment"

"The remark, which barely drew notice in America, is all over the Polish news today. On the country's largest television station:"

Poles Demand Obama Apology For "Polish Death Camps" Comment

Polish officials call on Obama to apologize for ‘death camp’ remark | JTA - Jewish & Israel News

In reading a bit more background, I find that among those who should know this term is and has been considered insulting to Poles.

While I am obviously anti Obama my feeble mind went to those folks who have the job of preparing the President for these kind of events. This is something that they should know and should have impressed strongly on him.