Originally Posted by dougotte
This was the only redeeming part of the episode. You could see it in Glenn's eyes - the realization that they'd crossed a boundary between justified killing (of walkers) vs. killing other healthy humans just for the sake of protecting the tribe and resources.
Was that really all it was? Don't forget, the one guy attempted to draw down on Rick. The other guy was pissing on the floor and was likely intending to shoot Rick in the back. These guys were the definition of anti-social. They likely would make Shane look like a teddy bear.
Despite civilization being gone and the law being non-existant, they did this in the presence of someone they knew was a cop. Even the comment about where the guy got his gun was fishy, despite the backpeddle about him "already being dead". The guy said he got the gun off a dead cop - not some dead guy - not just found it - he got it off a dead cop, like it was some source of pride. When Rick tells him he's a cop, the guy laughs it off, but Rick knows what's up.
These guys intended to take Rick out so they could force the other two to take them back to the farm. Who knows what they would have done there.
Rick did exactly what he had to do, not only for his own safety and survival, but that of the others in the group. Had those two guys walked out of the place (even if they intended to follow the trio back to the farm), Rick would have let them and dealt with them later if necessary.
This wasn't shooting people to keep them away from the secret fort. This was defending yourself from being killed by what likely could be described as "road pirates".