Felix Gaeta recently learned that a) the man who cost him his leg to further Starbuck's search for Earth was in fact a Cylon; b) the population of the late great Earth would appear to have been entirely Cylon; and c) the Eight he thought was working with him to free some of the prisoners on New Caprica was in fact using the lists he gave her to build lists of prisoners to be executed - in other words, he collaborated (unknowingly, but still) with the Cylon occupation to kill his own people. The primary lesson he's taken from all this? The toasters can't be trusted. They'll betray you the first chance they get. (The lesson is false, but it's what he's learned nonetheless.)
Now the Admiral is insisting on installing Cylon tech that nobody else in the Fleet can understand - and permitting the toasters into the engine compartments of every ship in order to do the installation? In Felix's mind, the Old Man must have lost it entirely, and this plan is putting the entire human race in jeopardy. By his own reasoning, he must act to stop it! And unfortunately, he's now fallen into the orbit of Tom Zarek, former terrorist and master manipulator, who just wants to be in charge, even if all he gets to be in charge of is the tattered remnant of a race tearing itself apart unto oblivion. I think Felix is only beginning to realize what kind of man he's allied himself with - while he could excuse Zarek clocking Laird on the hanger deck for being in the way, it's a lot harder to rationalize away the Marines opening fire on the senior officers after Felix just ordered them taken into custody.
So, like I said, poor Felix Gaeta, who's so blinded by hs concept of his "duty", and his bitterness and hatred toward the Cylons, he let himself be led down the road to Hell by Zarek...
(Of course, if he doesn't correct course soon, I'm still going to be cheering when Kara Thrace beats him to death with his own prosthetic leg.)
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Sodium is a metal that reacts explosively when exposed to water. Chlorine is a gas that'll kill you dead in moments. Together they make my fries taste good.