In "Funeral for a Friend" after Higgins and Redwing get captured, and remaining roughnecks start to make plans. Higgins and Redwing are standing with the group.
Rico's rank on his helmet is not consistent, when he's promoted to sergeant in some episodes the mark on his helmet is still a single chevron instead of three.
During the taking of the beach in the Tesca Campaign, the armbands the Roughnecks wear for Carl disappear and reappear from shot to shot.
In episode #26 "Metamorphosis", when Zander-bug has Doc cornered in the Med-lab, Doc refers to Zander as "Lieutenant" even though Zander's rank is Major. It was speculated that Zander was demoted, but General Redwing reports that he accessed computer files as "Major Zander Barcalow" in episode #28 "The Mission".
Doc has "Doc" written on his helmet instead of "LaCroix" (his full name is "Corporal Richard LaCroix").