Green Granite
By the tenor of your post, you seem grossly to misunderstand where the burden of proof lies in this case. JP is not correct: The burden lay on Wratten and Day to prove that the crew were grossly negligent "beyond any doubt whatsoever." Therefore, it is not for us to prove that control jamming (or any other possible cause) was the cause of the tragedy, it was for the reviewing officers to prove that no cause(s) other than gross negligence by the crew resulted in the tragedy.