If an evil person makes a true statement, is the statement any less true?

Per CNN: NORTHPORT, New York (AP) -- Two high school seniors picked quotations from ***** ******'s book "**** *****" to appear under their high school yearbook pictures, prompting school officials to apologize.

"The quotes were picked by Christopher Koulermos and Philip Compton, both 18. Koulermos' read "Strength lies not in defense, but in attack." Compton chose "The great masses of people ... will more easily fall victims to a big lie than to a small one.""

My question is, how important is it, who said these things?

The first quote ("Strength lies not in defense, but in attack.") could just as easily be from any number of military strategists. It could also be from Mr. Rumsfeld and Mr. Bush.

I could imagine the second quote ("The great masses of people ... will more easily fall victims to a big lie than to a small one.") coming from Machiavelli, and his work is often quoted. I've heard the same thing from many conspiracy theorists and had the same thought myself many times under the current administration (formulated as "this is so outrageous it can't be true...but what if it is?...no one would believe it!").

But, because Hitler had these thoughts and wrote them in Mein Kampf, they are taboo. The school is writing a letter of apology, among other things, for having had the quotes included in the year book.

So, this of course raises the question about truth (philosophical or otherwise). Is it any less true if an evil/crazy/deceitful person says it?

If these students had chosen to write something about Hitler's racial theories, then I could understand offense being taken, and would be disgusted myself. However, there is nothing unique to Hitler in the quotes that the students chose.