When Major De Lucca drives into the castle, he parks his jeep parallel to the stairs. Later, when he emerges and sees Mara, the jeep is almost perpendicular to the stairs.
An illuminated "exit" sign in a German Gästehaus in 1945. Highly doubtful.
De Lucca is suspicious of the killing of the assassin and states that Shelley was shot in the head when he clearly was only shot once in the chest.
Near the end Webber and Mara ski away from the chalet down the hill. They arrive back at the chalet skiing down from uphill of the chalet.
De Lucca investigates the car accident and finds the rubber bullet that was used to shoot Patton lying outside the car on the ground. The bullet was shot into the car and struck Patton and would not have bounced back out the window in the direction from which it was fired.
Col Rogers states that Patton has been ordered to return home by Truman on Dec 10. There is no reason for the assassination attempt to be executed if Patton is no longer going to be responsible for finding the missing gold and is leaving Germany.