Doc has to bite his lip when Raylan stops him. Zombie apocalypses, as with any other trying circumstances, brings out the worst in people; just makes people do the things they are already capable of. They also bring out the best in people. Mathias is evidence that there's no need to be swinging barbwire bats around.

"It don't matter why! If you done me wrong I'll shoot you. I don't bring Winona and Willa and all of goddamned Harlan to make 'em watch the spectacle. Could you live with yourself when he snaps one day and goes to town on Malcolm like that? You weren't here to shovel your entrails and brain matter off the ground to bury what shreds of your rotting flesh were left." Not that what Raylan went through in the 'Other Mathias' wasn't traumatic. But that's neither here nor there.

"Goddammit, Raylan." You're making his blood pressure spike, tugging on all these tightly shut compartment doors threatening to make him spill.