Originally Posted by LadyJ
Nah. I think he was alarmed at the number of walkers in the horde that was following the train headed in their direction and decided to pack up his peeps and gtfo.
I think the opposite, that it is not really plausible. A long distance separates the town from walkers where you left them behind, and there is very few chance this guy saw the railroad from above. Also, there are a lot of walkers already infesting the city. It does not really change their situation.
You should also remember that one of the people in Vernon's group , an old woman, seemed really sick, and could'n't stand up. A train is a perfect way for them to travel injured people.
Another guy in the group said he was from Macon, if you played it by telling them that you did not come from here (Lee says he is from Macon). They might have headed back for whatever are their reasons.
And obviously Vernon's group does not have Clem. They were not the one playing with the talkie-walkie, and there is no way Vernon is a kidnapper.