Continuity mistake: When Steve is bathing after the first fight on the island, he has a bandage on his shoulder suggesting a wound, but his shirt is not torn at the shoulder.
Continuity mistake: At the end after the massive explosion on the runway, two German soldiers get up unscathed and remove their gas masks. They suddenly appeared, as no one else was there, only Diana, and they are only a few feet away from the crater.
Continuity mistake: At the end when Diana is moving through the crowd approaching the memorial wall, the Scottish sniper is behind her. In the next shot when she turns around, he is again behind her.
Character mistake: Both Diana and Steve go to sleep on the sailboat at the same time. Who is making sure that they stay on course? Navigating a sailboat is vastly different than a power boat, which is why someone is always "on watch" to make sure the boat stays on course. If they're both asleep they could end up anywhere.