If a word of Jessie's ramblings had been true, I would think that the police would have found Chris' penis in their shoulder-to-shoulder search of the area. If Jessie told this tale to the officers (which I don't accept as gospel), it is meaningless as it was not under oath, which makes it little better than hearsay. Finally, the statement that Jessie was asked if he had anything to say is, IMO, very strange. Since he had already been convicted, why would the officers think he had a statement to make?
IMO, what happened is that the transport officers were told by superiors to try to get Jessie to talk. IMO, their role in getting this "statement" was much more active than they have indicated. In fact, I would not be at all surprised to find out that they helped Jessie's memory a bit. Of course, the story Jessie told this time was as unbelievable as all of his other stories, especially in light of the information that has come to light since the trials.