The wetsuit theory was one of the most stupid I've ever heard: was that given in court?
Police thought there was some mileage in the wetsuit theory, after RB's suggestion that JB could have worn one and their discovery of a top and bottom part in his bedroom at WHF. But the head-piece was found at his cottage, which struck Julie as odd because she seemed to think all parts were usually kept together there. And Bamber also told her that he would wear dark clothing and a mask.
That was another potential piece of evidence which wasn't investigated thoroughly enough - if miniscule but measurable spots of blood from the victims had been discovered on it, it would have been game over for JB. Although if he'd ever thought of wearing one, the idea was probably ditched as it would have restricted and hampered his movement anyway.
The shower-rose was found dangling and the tray might have been wet if he'd used them, but that wasn't significant because Nevill normally had a shower before going to bed.
Not sure whether the wetsuit was brought up in court, although RB might have mentioned it when questioned.