That is easy.
The WILD ACCUSATION will incite riots on the arab street and will cause an embarassment to the administration and will push the talking point of the DNC that the USA is weak militarily.
IF THE TRUTH shows the usa is strong and did the right thing and the terrorists USED civilians to hide behind, well that truth can be burried on page 347 on a tuesday appology section.
Murtha, the liar, is only worthy of derision and contempt. He is an embarasment to those who wear and wore the uniform.
He is also an embarrassment to the US Congress. Unfortuantely there are more than a few of those.