Robert Shaw earned $350,000 for his role as the German Panzer commander, more than he had earned in his entire career up to that point. That amount, after adjusting for inflation, would be equivalent to $3 million in 2022.
This film was denounced by former President (and Supreme Allied Commander in Europe during WW2) Dwight D. Eisenhower soon after its release in a press conference due to its glaring historical inaccuracies.
Entirely shot in Spain ,which doesn't share much in the way of physical similarities with the snowy forests of the Ardennes in Belgium.
The film's senior military advisor, Brig. Gen. Meinrad von Lauchert, was the commander of the German 2nd Panzer Division during the real Battle of the Bulge. He then had the rank of Oberst (Colonel). Near the end an officer states that a German unit was within five miles of the Meuse River. Coincidental or not, that unit was commanded by von Lauchert.
The film makes it seem like the battle only lasted for a few days. In reality, it lasted just over a month.