Where was the Queen
If I remember my timeline correctly, this occurred during the period after the death of George VI and before Elizabeth II was coronated but no matter.
She had the absolute right and duty not to allow this obvous miscarriage of justice occur. And if this clown of a Home Secretary Fyfe refused to do the right and proper thing, then the onus was on her to make her displeasure with the execution of an obviously mentally retarded and innocent young man to occur.
That makes her a murderer period.