Yes the interviews do him no favours but again it could be claimed he felt he was being "put up for offer". And further more he knew who the bidders were.Also he has no clue what the Police have been told. What they might spring on him if he gives a clear amswer.
Again if he is truely innocent, all of this wouldn't unduly bother him. He would have answers. An innocent man, would,I think be much more proactive with his denials. His demeanor etc begs the question.."what have you got to hide"?
Believe the police confronted him with what they had got at the time - Julie's accusations, windows, bike, Sheila's two shots, wills, caravan breakin, silencer, phone calls to Julie.
Bamber made no effort to deny anything. He had no valid defence & failure to convince the police would not get him convicted.
He would have to focus all his attention on the trial.