Other mistake: In this scene we see two scenes used twice in the film. Tarzan and Sandra are climbing up the rocky terrain and a few minutes later we see the same scene of them climbing up.
Other mistake: In 1902 at the German cafe, Kaunitz spits in Clive's face, and Clive promptly hits him, causing Kaunitz to fall down the steps. After this, several German students close behind Clive are wearing decorative ribbons to show their affiliations. The problem is the costuming department has used ribbons intended to mount miniature British medals for the 1914 or 1914-15 Star, British War Medal and Victory. These decorations didn't exist until 1918/1919 at the earliest. (00:36:01 - 00:38:01)