"CBS said it used several techniques to make sure the memos should be taken seriously"
What does that mean "should be taken seriously"? CBS had been saying they had used several techniques to make sure they were GENUINE. Now they have watered down the criteria to "should be taken seriously", a "passive-voice" construction that begs the question "taken seriously by whom"?
It seems that CBS is trying to lower the bar from "these documents are real" to "it was imporant to let the public judge for itself." Or is "taken seriously" intended to mean "passed off as genuine on network television news?"
Forgery DOES take several techniques.