During the "slave market" dance number Marge Champion at one point has a small basket on her head. It falls off and lands on the ground between her and Gower. They pull in for a closeup and when they pull back the basket is gone.
The elephants shown in the film are Asian elephants. Hannibal was from Cathage, on the continent of Africa. The elephants he used would have been African, too, not Asian.
As Hannibal surveys Rome, the famous Colosseum can be seen in the background. However, this film is set in 216 B.C. and the Colosseum was not built until nearly 300 years later, around 80 A.D.
Varius states that the Cathaginians have 60 elephants, but in reality they began the march with only 38 and most did not survive the journey over the Alps.