Actually, I rewatched it & the Tru Blood/Terriers guy did go for his gun. It was pretty quick.
Oh yeah, the guy definitely was going for his gun. That is not something Rick would have done lightly. It was a last resort kind of thing since he saw how the situation was unfolding and there was really no other thing to do.
He was being defensive the whole time about the farm and their setup, which I saw as an ironic switching of positions. Hershel was the one protecting the farm and his family, trying to prevent outsiders from intruding, and now maybe Rick has some insight into how Hershel feels to have others try to invade your space.
Also, I love that you referenced him as the True Blood/Terriers guy, because those were the only two things I know him from really haha. I was happy/surprised to see him show up for an episode.