Often GIs are rushing into the lines causing them to fall under the guns of fellow American soldiers. In reality the soldiers would have used challenges and responses (codewords) to identify friendly troops.
When Saunders radios in to King 2, he doesn't say "King 2" before he starts talking. "King 2" is dubbed in.
When the German moves Kirby's "body" with his boot, then walks away, the boom mic shadow appears at the bottom of the screen and moves upward.