Well, from what I've read, it is recommended that for any kind of apocalypse, it's best not to announce that you're any kind of doctor or scientist, because it increases the likehood of people targeting you. Plus, if you were a scientist and you have a military guy who appears to be going psycho when it's clearly a bad idea to drive into a megaherd of Walkers, wouldn't you lie to him to protect you, him and the others with you from a potentially bad idea he is blindly willing to do?
And it's hard to actually trust what is said on Talking Dead, let alone what actors and producers can or can't say. I point out an example with Katee Sachkoff in Battlestar Galactica. After the episode of "Maelstrom", from Season 3, Sachkoff, when at conventions, she acted as if her character was permanently written off when people asked her about it. Even the opening credits of the show had her named removed from the credits after that episode. Yet, Starbuck came back at the end of Season 3 (and her credits was added at the end of the Season 3 finale after her appearance), and her name was put back into the opening credits in Season 4. So, just because we hear the actors and producer say "Yeah, Eugene's not a scientist" after what is revealed in the episode doesn't necessarily mean that it's fact, especially if they're planning on broadsiding people with another twist about Eugene.
But then again, like I said, it was a weird idea, and I could very well be wrong. I mean, for all we know, they're playing it exactly as the comics.