Revealing mistake: After Dualla shoots herself, Gaeta hobbles back into the room. While the effects people made sure his real lower leg was erased from view behind his upper leg, they forgot to remove the shadow of the lower leg being cast upon the steel floor. The shot then changes away and returns to find the shadow has now been fixed the second time we see it.
Revealing mistake: Just after Tigh announces that Centurions will be "pouring in at platoon strength", the next shot shows those Centurions marching though the Galactica's halls. None of them are casting shadows despite the various nearby light sources that should be causing such shadows. This is most obvious looking at their feet.