At the end, Crittenden in London talking on the radio calls himself 'Mama Bear', calling Hogan 'Goldilocks'. These have not been their usual code names in the past.
When one of Colonel Crittendon's men is shown, he is smoking a short cigarette.
When he is shown again his cigarette is now much longer than before.
While Kinch is taking down the coded message, LeBeau is leaning on Carter's back with his right arm.
When Carter starts talking LeBeau is no longer leaning on his back.
When Carter stops talking LeBeau is now leaning on his back again.
In the epilogue, when Schultz enters the barracks to announce the roll call, he wears the aiguellette of an aide-de-camp. Only officers filled that role, not a sergeant.
The steering wheel of the truck that Schultz get in is on the right. In other cases, a truck is shown with the wheel on the left. Normally in Germany, the steering wheel is on the left.
When the air raid siren goes off in the hospital, Colonel Hogan and LeBeau hide in a room. When they come out of the room less than 10 seconds later they are both dressed in hospital scrubs.
That would not be enough time for them to change out of their uniforms and into the hospital scrubs, or even to put the scrubs on over their uniforms.
When the men are in the woods looking for the commandos, they hear the clicking sounds, think it is the cricket device snapping. It happens to be Carter cracking his knuckles. However, Carter is wearing gloves. Any knuckle cracking would be barely audible while wearing gloves.
When Schultz is ordered to start the truck that may explode, when he gets in the truck his helmet is not secured with a strap. After the explosion the stuntman falls out of the truck and as he is on the ground his helmet is securely strapped to his head. Camera pans to Klink. When the camera pans back to Schultz laying on the ground, the helmet is not strapped.
When Hogan is talking with Klink (in Klink's office) about the truck being ready, there are several times where the stage lights reflect off Klink's monocle.
Considering the number of memory gaps that Col. Crittendon had regarding the hospital, Col. Hogan would have made absolutely certain that the person in the room that supposedly contained Rommel actually was Rommel.