You and Sam had to come up with something to save a family from a ghost. You had an idea and Sam had another. Both decided to go with yours because it seemed like the most reasonable one.
But at the last minute, you failed to save the family and only one person survived. The person Sam saved.
When both of you come back to the motel room; Sam took his frustrations out on you, which started a small argument. You were already feeling guilty and this made it worse.
He knew he was wrong, but he couldn’t help it. He felt guilty too, and there was no one else around to blame except himself and you. He left the motel room and was gone for hours. You called him, he didn’t answer. You texted, nothing. You never expected him to do something like this, giving he was very supportive.
You are on edge waiting for him to come back. And he finally does, he walks in and close the door behind him. And without looking at you, he starts to take off his boots and flannel shirt, probably wanting to take a shower and get ready for bed. He looks terrible, but so do you.