If the witch had led an evil and improper life, she was guilty; if she had led a good and proper life, this too was a proof, for witches dissemble and try to appear especially virtuous. After the woman was put in prison: if she was afraid, this proved her guilt; if she was not afraid, this proved her guilt, for witches characteristically pretend innocence and wear a bold front. Or on hearing of a denunciation of witchcraft against her, she might seek flight or remain; if she ran, that proved her guilt; if she remained, the devil had detained her so she could not get away.[1]
If you argue that an obvious bug is evidence of NSA involvement, then you must also believe a subtle bug would be evidence against NSA involvement. You can't have it both ways.
1. From Conservation of Expected Evidence http://lesswrong.com/lw/ii/conservation_of_expected_evidence...