Other mistake: When the band is playing in the mess-hall you hear the drums playing along. When Ryback enters the mess-after after the take over, no drums are on stage.
Continuity mistake: At the party, you can see the cook standing next to the stage in one shot. Then, you can see him slicing a piece of meat on a table nowhere near the stage. Then, in the next shot, he's back next to the stage. Not enough time in-between shots to move the distance that he did.
Visible crew/equipment: As Stranix follows Cmdr. Krill out of the hatchway, he looks around. As he does, the camera crew and boom mike man are reflected in his shades.
Factual error: When Ryback uses a cutting torch to open the locked door and free the six sailors, he (correctly) puts on a pair of goggles first. Jordan Tate, however, just stares at the torch unprotected as he cuts through a thick metal door. While the exposure time that she experiences is fairly short, she never even flinches, and suffers no ill effects. Especially for someone with no experience with such tools, she should be wincing in pain and looking away or squeezing her eyes shut.
Factual error: In the last scene, where Chief Ryback is at his captain's funeral, he's in his dress blues, and you can see his rating insignia to see that it is not of a cook (Mess Specialist/MS, now known as "Culinary Specialist/CS"), but that of a Yeoman. While in general, this still matches up with the history of the character (where Krill mentions that he could only be a cook or a yeoman after losing his security clearance for punching out his OIC), he wouldn't be cooking, he'd be doing office work. (01:38:42)
Answer: Also, the more times the scene is practiced or additional takes, the less funny it is to the actors. So, it would be easy by the time of filming for Strannix to not laugh. Just like if you have seen a classic comedy TV show, the audience is always laughing because it's generally their first time seeing the scene when filmed. But you as a viewer, seeing the show a hundred times over the years, do not laugh because you have seen it so many times. That, to YOU, it's not funny anymore. Same rules apply here for the actors while filming.