Please explain the ending of S5E5 of The Walking Dead to me

Question

If you haven't seen The Walking Dead S5E5 yet, here's what happens:

At the end of the episode we see Jim finding his wife and kids dead, and the guy with the mullet (whose name escapes me) comes limping towards him shouting, "Jim! Jim!!" with a few walkers giving chase. Jim comes over and kills the walkers, and then Dr. Mullet says to him, "I need to get to DC. I can save the world." or whatever he says exactly.

So, if Jim knew Dr. Mullet well enough from the very beginning for the guy to know his name, how did he not know he was lying that whole time?

Answer 1

The character's name is Abraham, not Jim. He heard Eugene yelling "Help, help me" followed by "It's them, get 'em". This may have sounded like "Jim" but according to the subtitles (via Amazon streaming), those are the lines.

After Abraham killed the walkers, he turned and was walking away, in a daze, when Eugene said he was on a very important mission. This is what got Abraham's attention and gave him a sense of purpose.

Remember, this flash back follows Eugene's revelation.

Eugene had just told the group that he was not a scientist and does not know how to stop the infection and the walkers. Abraham knocked him out then fell on his knees and remembered their first meeting. Abraham had given up and was about to commit suicide. He answered Eugene's call for help, then appeared to be going back to commit suicide near his dead family, when Eugene's declaration of a mission gave him purpose again.

At the time of the flash back, they were strangers and had never met. So Abraham did not know anything about Eugene at that point.