Critical Research Failure: in the pilot, Vincent, a doctor, enlists in the army and becomes a grunt that joins a program where he's experimented on. As a doctor, he would have been commissioned as an officer. Admittedly, this would have decreased his likelihood of being an experimentee (vs an experimenter). The funny thing is, they could have made him a (para)medic (an enlisted position), and still given him the medical background.
Moral Event Horizon: Gabe murdering Catherine's friend, Beth, without blinking an eye. This is the same guy who once viewed his beast powers as a curse. Later goes on to murder Cat's FBI informant and comes severely close to killing off J.T.