Please explain it to me.
So the only plausible explanation for Andrea not going back for the truck was that Andrea was stupid and that, though the writers knew the truck was there, Andrea could think only of running into the woods and getting away.
However, the very fact that Andrea's death was meant to be the big moment of the finale shows that the writers are completely oblivious to how reviled Andrea was and how stupid she acts as a character. In fact, based on their expectations, it would be reasonable to assume that they view Andrea as a likable, capable, character. We see her, at times, easily dispatch waves of zombies singlehandedly. She's shown to be more competent than most of the citizens of Woodbury and looked up to by many of them as a leader. Even Rick, who is a coldhearted bastard, is tender toward her in her final moments. She borders on Mary Sue territory, at least in the eyes of the writers.
But to the fans, she's reviled. It's not because the writers don't WANT her to be liked. They are just terrible writers. Fuck, Merle's death was more moving than hers, and he was a psychotic racist drug addict murderer.
So, IMO, this is conclusive evidence that the truck SNAFU was the result of bad writing, not legitimate storytelling.