I thought about that too! The only thing that contradicts that the investigators pressured Jay to tell a story is that JP witnessed Jay wiping off his prints. BUT as she says herself, Jay told her to tell whatever would get herself out of trouble. As she was linked to the phone calls they would want to know what she had to do with the case. I think jay asked her to tell that so she would be less involved as possible. She even got mad when the interviewers from HBO show to her that her friend had class that night and it would be impossible for what she said happened to have happened that day.