When Dr. Lewis tries to go up the stairs to the third floor of the house, he is stopped by Eddie holding a gun. When he comes back down the stairs, a large, distinct, moving shadow of the boom microphone can be seen on the well-lit wall behind him. (The same shadow can be briefly seen when he ascends the stairs, too.)
Whilst the bombers are attacking the German submarines, they change from single engine and twin engine aircraft. Not only is this a continuity error, but single engine warplanes did not at the time have the range to attack German submarines in the Atlantic Ocean.
When the bombers are attacking the U-boats, one shot shows the interior of a bomb bay and the release of the weapons. Just before the brief shot ends, one straggling bomb is shown dropping down a bit but hangs up in the bomb bay.