Yeah and towards the end when Louise rang his sister, she seemed like a normal person, owned her business etc and she said he was a nasty person, Rob had kind of made out she was the horrible one but his words aren't reliable
Spoiler:
...I was so sure that it was David from the first episodes but then I did a complete turnaround...because that would have been obvious and I knew that it wouldn’t be obvious..it would be the least obvious twist...I just thought that it would be someone living......which it was, but you know what I mean...I think also that, watching Sucker Punch so recently was influencing my thoughts as well and the control of those girls etc...
...but with Rob, we were mostly looking at the character with sympathy...I might actually have a rewatch quite soon tbh, to look at any clues with a different eye../Behind My Different Eyes.....