In his summing up the trial judge raised an entirely new speculation. This was that after John had been seen in the garden at 11.30pm, when the car was still on Mrs. Bolshaw’s driveway, he could have at some later stage returned to 5 Buffs Lane and taken the car. This was not something that had previously been suggested by the prosecution, so had not been rebutted by the defence.

Such a speculation would explain away any alibi evidence. But the man seen with the car was not John, and the theory does not make sense when the fibre evidence is analysed.

• Forensic evidence revealed that dark brown fibres found on the negligee, bedroom stool and the lower bed-sheet matched fibres found on the driver’s seat of the car.

• The obvious inference is that the killer was wearing clothing that shed the brown fibres both when he killed Mrs. Bolshaw and when he drove the car away.
  
  
• If John had already buried the clothing which had shed the brown fibres found in the house, and had then returned to the scene of crime and removed the car, how did the same fibres come to be on the driver’s seat of the car? It is clearly impossible!
  
  
• Also, if John had killed Mrs. Bolshaw, why would he have undertaken such a considerable risk as returning to the scene of a murder to remove a car?
  
  
• Mostyn Avenue is approximately 3 - 4 miles from Buffs Lane. John would have had to walk through a built up area to return to the scene, yet no one saw him.

In raising the speculation that John had returned to the scene of crime to remove the car after he had buried clothing worn during the murder, the judge provided a new route for the jury to convict John. The defence had already deconstructed the Crown’s case, but this new speculative theory was extremely prejudicial to the defence. Although it was not a viable explanation of events, it undermined the alibi evidence which had been established. (See appendix 5 and appendix 6)