Taff Jones, namesake Stan, Bob Miller, Mike Ainsley, Anthony Arlidge KC, Judge Maurice Drake, and other deceased protagonists making their Ouija board tremble.
Probably more likely to be TFG and / or others who were on the scene early stages. Obviously, if still alive, nobody heavily involved in the 2nd investigation would cooperate with this type of investigative journalist who will have had sight of the submissions. That's too difficult an interview and would be shunned.
Remember, we only know that the jury were going to set JB free due to a moment of carelessness from an original officer in the case, because they were comfortable in speaking to CAL.