[Is it any surprise that Mercy is so quick to reply to McCree's aggression? It isn't entirely out of disdain for his method of "law enforcement" - her friend has just announced his intent to chase a serial killer publicly. She can't imagine this going any way but poorly.

She joins the call despite clearly having a patient behind her. Once she's sure she's in the frame and connected, she props the device up so she can work and talk.]

Violence is rarely the best answer to this sort of situation. I agree the killer must be caught, but I do not agree that you have to be the one to do it.

[She doubts there is any use in bringing up the fact that there are police AND an entire network of heroes here to deal with this. With a sigh, she puts down her tools and faces the camera head-on with a stern frown.]

And put that awful thing out. Every one of those you put in your mouth takes a year off of your life. It's a miracle you're still alive between those things and this sort of behavior.

[Then she sees it. Or rather, she registers it. Her face forms a cold mask. What did she miss? Why didn't he come to her when it happened? She takes a deep breath.]

Jesse McCree. You need to come to the Outpost and both explain to me what you did to your arm and allow me to make sure it was installed correctly.