Gomer Pyle is wearing two awards, the National Defense Service Medal, and the Marine Good Conduct. In the first few scenes, the NDSM is to the wearers right of the Good Conduct Medal. Later, the GCM is properly on the right side of the NDSM. - Then in the last scene - they are incorrectly being worn.
In the dance scene at Jill's house, black tape is briefly visible on the floor marking where the extras are to be dancing.