After Curly says the line, "Oh, a snobbess?", the Stooges are, for some reason, looking down at the ground and Larry is standing in a different spot than before.
When Curly gets his head stuck in the cannon, his hands are by his side, but in the next shot, they are holding both sides of the cannon.
When Mrs. Dare faints, Moe yells for water and Larry runs to get it. Larry is seen pouring water into a glass held in his left hand and drinking it. In the next scene, Larry is drinking the same water from a glass in his right hand.
Sgt. Dare makes many mistakes as he commands the new recruits. First off, when the stooges accidentally do a left face instead of right, he should've immediately picked up on that and corrected them on the spot (by whatever means necessary). Also, as he is marching, he is marching close to up in front of the troops, and when he has them do an about-face, he runs to get into a similar position as they continue marching. Any experienced leader who is marching a platoon knows to be positioned as central to the platoon size as possible in order to properly march in lock step with them, and so when he stops them and has them face him he is once again central to the size of the platoon.
When Sgt. Dare is reprimanding the stooges, just before he had focused on Curly, you can see that Curly was beginning to pull something (like a piece of fruit) out of his right pocket, but then there's an edit, and the object is gone.
When the Stooges duck into a "bread line" and attract the attention of the people in line, the third person in line can be seen tapping the second person twice because he missed his cue.
When Sgt. Dare and his army are marching back and forth on the base, you can hear strange thumping sounds in the soundtrack that the boom operator picked up.
When the Stooges enter the enemy's headquarters, Larry can be seen tripping on the rug and almost falling.
When Curly puts his rifle over his right shoulder the first time, it almost hits Richard Fiske, playing Sgt. Dare, on the head.
When Mr. Dare is chasing the Stooges in and out of the front doors of the apartment building, the middle door can be seen open, even though nobody goes
through it.
Moe's line "Hey, wait a minute!" is played too early when Curly's head first gets stuck in the cannon.
When the enemy general is saying a line of dialogue in Pig Latin, his mouth does not move during the first two words.
The 3 stooges are affected by the laughing gas but the enemy soldiers who capture them aren't affected by the laughing gas.
When Sgt. Dare is spraying the garden hose in the bayonet target bags containing the Stooges. Moe spits water in Sgt. Dare's face, but no water was sprayed into his bag, so how would there be water in there?