In real history, Tesla had nothing to do with WW2 codebreaking. It was the mathematician Alan Turing, who made the conceptual advances (inventing the computer in the process) who broke Enigma enabling the Allies to win the war. After the war, a not so grateful UK government convicted Turing of being a homosexual and chemically castrated him, causing his suicide.
As Zimmerman's squad moves toward the Nazi secret weapon, a Nazi soldier sees them, gets shot, and delivers a Wilhelm Scream. This is the first Wilhelm used in the series.