The troops depicted at Arzew in the game are German troops, when in reality the soldiers that the Rangers faced were Vichy French troops.
Incorrect reloading animations.
Mustard gas causes severe blistering, and a gas mask is not enough to shield against it.
One of the alarms is improperly looped; during the looping, the alarm buzzes twice in a second while during the rest of the loop it buzzes less often.
Small arms did not use tracers in the Second World War (except for machine guns).
Since no soldier walks around with partial magazines of ammunition - especially for the M1 Garand - the maximum ammunition should be capped at a multiple of the maximum ammunition per magazine.
The map on the main screen is of postwar Europe (note in particular Poland's borders). The one in the briefing room is from 1938-39, but represents the borders the Allies would have recognized at the time.
The flag for Juno Beach is the post-war Maple Leaf Flag, and not the Canadian Red Ensign which was Canada's flag at the time.