If Nathaniel Summers hadn't hidden his injury from Suzanne Saunders after being beaten up by those thugs, he wouldn't have been ambiguously involved with Jade Carlson for the entire following year.
At that time, he hadn't yet been hypnotized.
Although it's true that his lower body was injured, if he had just followed the doctor's orders and taken his medication, and waited patiently, he would have eventually healed.
But he was too hasty, and that's why he was bewitched by Jade Carlson into receiving so-called psychotherapy.
Even if, stepping ten thousand steps back, he was hypnotized later on and couldn't stay away from Jade Carlson, it wasn't as though he was completely without reason. If only he could have taken the initiative to be frank with Suzanne Saunders and explained things clearly, he wouldn't have reached the point of no return in the end.
Suzanne Saunders was busy with work and didn't fully step into the role of a wife quickly enough—she was indeed at fault.