Other mistake: Troops being flown in are in a glider towed by a bomber. People on the ground hear airplane engine difficulties and then a plane crashes. There's no attention paid to the people in a glider. They assume all have perished, but where are the people in the glider?
Other mistake: When Knut and Rolf leave Anna in the car on their way to plant the explosives on the ferry, they instruct her to wait no more than 2 hours for them. Once on the ferry, the earliest time seen on the alarm clocks is about 01:10 so we can assume that Knut and Rolf left Anna sometime before 01:00. When they return to the car after the explosives have been planted, you get a brief glimpse of Anna's watch which shows the time as 03:35; a full 2 hours 25 minutes after the 01:10 we saw on the clock yet Anna states that there are 9 minutes left. (01:44:06 - 01:53:57)
