I think, and seem to have many people in agreement from either camp, that the police investigation was extremely poor. Just an opinion.
I don't really go in for all of these silly quotes, not my bag I'm afraid. 
Yet you're quite happy with the concept that any anomaly that has come to light in the secondary investigation that gunned for JB, is merely a benign mistake. All of the mistakes in the scondary investigation (which appear to many as resembling tried and tested corruptive practice among 80's police forces), are perfectly acceptible...
Whereas any mistakes that went on prior to JB being suspect in the initial investigation are representitive of poor professionalism on the part of the officers concerned.