In my opinion the problem with having just one person giving the verdict is that, as hard as you might try, it is impossible to be completely impartial. You will always have an overriding feeling, one way or the other. Juryies aren't perfect but they normally work out the right verdict which in this case, in my opinion the judge hasn't.
Forget the witchhunt, my reasons for believing his guilty of murdering his girlfriend are that I don't believe he got out of bed after hearing a noise and then did what he said in his testimony before picking his gun and going into the corridor before shooting four shots through the toilet door, without knowing his girlfriend was not in there bed still. Theres no way he would think she was still in the bed.....
I believe any unbiased jury would have found him guilty on that point alone.