could it be possible.....
.... that Noah actually wounded himself? I know this seems like a stretch, and it could very well be anyone (the guard, the angry brother-in-law, someone close to the Lockhart family) but hear me out. Perhaps someone else has brought this up but I didn't see it.
The scene at the end of last night's episode shows Noah standing over a sink, and the last piece of silverware that he is washing is a sharp looking knife. We sort of experience the "break-in" from his perspective, supposedly hearing a door open and footsteps walking down the hall. However, we don't see a person, just a sort of shadowy figure. Noah kept his eyes forward the entire time after turning back when he thought he heard the door, and sweat is beading off him like crazy, like he is about to have a full-on panic attack. Could it be possible that Noah experienced some form of psychosis and did it to himself without even consciously realizing it? He has obviously experienced a bunch of s**t and his PTSD about it all (including the guard) may have caused a mental breakdown. I'm not even convinced that the guard is actually following him..... he could be imagining it. Just a thought.