When a small patrol attacks the farmhouse they have to return to the wall. Lloyd Bridges is shown throwing his rifle over the wall with a bayonet attached. The next scene shows his bayonet in its scabbard on his back pack.
In the note Tyne sends Rivera regarding the attack, Tyne states he will signal at 11:40 with whistle and the attack will commence five minutes later at 11:45. But when Rivera checks his watch he states it's two minutes before 11:45. Shortly after, a watch is shown and the time is 11:44. Tyne blows his whistle afterwards and Rivera states it's right on time; and the soldiers in the river state it will be five minutes before the attack begins. At this point it should be only 11:40.
When the American's are caught out in the open in a sparse field, they notice a "German" plane getting ready to attack. They head for cover in a nearby ditch. As the "German" plane attacks it's in reality a P-51 used for the movie. They shoot down the plane. As the plane descends and is about to crash, the view changes to actual footage from WWII aboard an aircraft carrier. The plane splashes into the sea.
When taking a 10 minute break, the soldiers state that it is 7:30 am, but the shadows indicate that the sun is clearly high in the sky, more like noon.
When the platoon ambushes the German half-track, a grenade explosion causes one of the tracks to come off the vehicle. Later scenes show the track still in place.
Other than rank insignia, none of the soldiers' uniforms bear any markings, whatsoever. It was standard practice to mark soldiers' helmets with chalk numbers so that they would know which landing craft they were assigned to board for the invasion. It was also standard practice to wear insignia to denote the soldiers' units for identification purposes, although sometimes the shoulder sleeve insignia were removed to impede enemy intelligence gathering. Also, the soldiers' helmets are shown buckled at all times. It was common for soldiers to leave their helmets unbuckled, as there was a belief that, in the event of a nearby explosion, the helmet would break the soldier's neck when it reacted to the concussion.
The soldiers are wearing a coverall type fatigue uniform which the army had determined to be impractical for field use by 1942. The invasion troops at Salerno did not wear this type of uniform.
When the platoon is being strafed, the airplane that attacks them is a P-51D Mustang, although it is intended by the producers to represent a German or Italian plane. Machine-gun bursts can be seen in only two guns - one in each wing. Me-109s, FW-190s, and C-205s had guns mounted in the nose of the aircraft, rather than just in the wings.
An American half-track is portraying its German counterpart.
After the platoon has destroyed the armored car, Rivera and two other men are walking along the road in combat formation. Rivera and his ammo bearer, who are talking to each other, are walking at a brisk pace while the man behind them is trudging along with a fatigued gait a bit slower, yet the distance between the men never changes. This was obviously filmed on a soundstage using treadmills.
When Dana Andrews puts down his rifle and picks up the fallen soldier's Thompson sub-machine gun, to prepare to assault the farmhouse, he doesn't grab the soldier's extra magazines to reload the Thompson. if he expended the rounds in the gun, which was common occurrence in assaults, he'd have nothing else to shoot with.
The German Machine Guns in the Farmhouse are not German. They are American Browning .30 caliber MGs.
The song at the end of the movie reads on the screen differently than it is sung: the first line reads "It's the walk", but is sung "It's that walk"; the third line reads "And it hits", but is sung "And hits"; the sixth line reads "It's the old", but is sung "It's that old".
When the men find the farmhouse and are deciding to storm it, they are by the tree. Two men are ordered to go down to the road. Richard Conte and another actor go. The camera pans back and you can see the boom shadow on the tree.