Is that ALL this is about? Contemplate, if you please, Experts contradict each other in Cadman-Harper controversy, originally from CP:
Former FBI special agent Bruce Koenig - who lists expert evidence about former U.S. president Richard Nixon's Watergate tapes and analysis of gun shots in the assassination of John F. Kennedy among his accomplishments - said more evidence is needed to judge the veracity and integrity of the disputed tape recording.
Koenig, who also performed an authenticity analysis of the Linda Tripp telephone recordings in the investigation of former U.S. president Bill Clinton, reported irregularities in the copy tape and portions where an earlier recording had been taped over, but concluded Zytaruk's original recording, his tape recorder and an external microphone if Zytaruk used one "are required to conduct a conclusive authenticity examination in a forensic audio laboratory."
Except the header is misleading. Koenig does not really contradict the report prepared by Alan Gough, one of the two audio experts that the Tories actually cited in their original 'plaint (Koenig's material was left out).
The other specialist hired by the party, Alan Gough, was less certain in his conclusions. Gough, co-founder of a firm called Integra View, concluded that the tape "is not a continuous recording of one conversation."
The interruption of words, changes of background ambiance, and changes of frequency response indicate that this may be three separate recordings. Any further analysis of these anomalies should be performed on the original recording and not on a copy," Gough said...
Was the recording of Harper's interview done over top previously erased material that still might have left audible traces? If so, then it is extremely doubtful that this old material would appreciably alter the content of the interview.