This is extra baffling to me on account of the nature of the Sans fight. Like... you have to be on your second playthrough at least and you have to willfully murder every single character in that game. Then you get to the end and there's a guy who is like "You can stop this anytime you want." and beats you a bunch? And that makes you PTSD'ed?
"I raped this person and they resisted, and now I have PTSD."
"I was beating this white man to death and a got blood on my new shoes, and now I have PTSD."