After his first encounter with the Terrible Trio, Bruce Wayne describes their masks as depicting "predators of land, sea and air." The newspaper depiction of the criminals, however, labels the one in the bird mask as "the Vulture." Vultures are scavengers, not predators.
When Warren Lawford, Armand Lydecker, and Gunther Hardwick are bragging about their accomplishments during the skeet shooting match, fraternity rings can be see on the right hands of both Lydecker and Hardwick. A moment later, the three of them place their hands on top of each other. In the close-up shot, only Warren's hand has a ring on it.
When Warren is about to chloroform Rebecca, she slaps his hand away. In the next shot there's no bottle of chloroform in Warren's hand, but in the shot after that he has it again.