After Shane had died, Rick had told Carl about everything he did. From sleeping with his mother Lori to trying to hook up with Amdrea. That made him despise Shane, even if he was good to him before.

You were never told this. Shane had treated you like his own, like his child. He taught you how to shoot, how to fight, and took you with him when investigating things.

Hearing you defend Shane whenever he was brought up made Carl angry. Why were you defending someone as horrible as Shane? It annoyed him.

Today, while you and the rest of the group were making plans to go investigate a nearby camp, you had brought up how Shane had told you that they should always head in quickly, because it would make them harder to shoot at.

Hearing you bring up Shane made Carl's blood boil, and he finally spoke up. "What, so we're going to trust everything that Shane told you now? Look where he ended up! We're not running head first into a camp." He growled, putting his hands on the table in front of him.