There's some interesting stuff online that's worth a look at mate which sheds .more light on information the programme makers didn't develop or use.
Its difficult to know how much of it yo believe but it does give more of 'the other side' so to speak.
I was going to mention that about some of the evidence. I read on one site that his ex fiance has released a load of information about what Avery was really like behind the cameras. She said she thinks he did it because the murder happened not long after he requested for her to be tied up and to have rough intercourse. Basically suggesting that he decided to try it with somebody else but obviously got rejected which led to the attack. His ex-fiance is hardly the reliable type though.
Some of the stuff that didn't make sense to me was how there were supposedly no marks on the bed posts from where the rope would have been rubbing quite aggressively, her car key was found in open sight on the floor, the specs of blood that were left in her car yet he had no cuts apart from on his finger (this also links to that vile of blood that had been unsealed), no signs of blood in the bedroom when it would have been all over the place etc.
I think I'm going to do a bit more digging though to see if there's more evidence against him. ATM though all I can think of is that half of it was planted, whether that's true or not.