This is deceptively tricky.
On the face of it, the answer is clear. Of course he is. Ever since three days after they met, everything he does and says has been wrong. He has dedicated his life to making Her miserable, and he's doing a great job. She doesn't know why she has stuck with him so long. Where is the great guy that she fell in love with? Well, let her tell him, she can't go on living like this. If he can't get his act together, she's going home to Mother for a long, hard think about the future. Dinner's in the dog. Bastard!
But in fact, it's more subtle than that. Words like "right" and "wrong" have no meaning except as defined by a good (and long-suffering) woman. Which means that she needs to witness the errors and determine 1. that they are wrong and 2. exactly how they are wrong and in what manner they ruin any slender hope of happiness that she was still clinging to. Until then, they are not fully defined and so, in a very real sense, they are not actually errors. Just the random acts of a hateful bastard!
But the man shouldn't take too much comfort from this, since he himself is not properly defined without her to explain why he can't wear brown with blue, he looks like a fifty year old toddler whose crack - fuelled mum leaves to dress himself out of the local skips, real people moved on from Fleetwood Mac when CDs came out and can he just for one frigging minute shut up about sodding global warming?
So the thing in the forest is not really a properly defined (and therefore responsible) human being. If it's not responsible for its actions, it cannot be wrong, can it?