When Hogan puts the film in the bone and gives it to the dog, the film is just inserted in the bone. After the bone is recovered, the close-up of the bone in Hogan's hand shows the film in the bone with a ring of some kind of putty around it.
Carter is supposedly photographing the new German Tiger tanks. However, a view through the camera shows stock footage of a Wespe... a German self propelled 105 mm howitzer.
The story that Hogan spins to Schultz about the dog being 5% of 20 different breeds is impossible. This would imply that the dog has only 20 great-great-great-grandparents instead of the normal 32.
The dog is heavily panting in some scenes. He would not be doing this in cold weather, but would be doing it under hot production lighting.
In the scene where Hogan picks up the dog after the dog finds the bone with the film in it, you can clearly see the Paramount water tower, the tops of some palm trees and the top of a telephone pole as he stands up.
In the stock footage of the Wespes, the German self-propelled 105 mm howitzers are shown on an open plain, while outside the camp is a forest.
When Hogan is talking with Hanna outside of Klink's quarters, a couple of palm trees are seen in the background. Germany does not have palm trees.