Other mistake: When Lawrence is looking at his wound in the mirror, it has slightly healed. Later, when Sir John visits Lawrence in the asylum, he shows the bite mark he got from the feral child to Lawrence. Since Sir John is also a werewolf, the bite mark should not be there.
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More mistakes in The Wolfman
Gwen Conliffe: It is said, there is no sin in killing a beast, only in killing a man. But where does one begin and the other end?
Trivia: Makeup artist Rick Baker has a cameo appearance in this film. He's the man who whistles to his comrades who are approaching the gypsy camp then a few seconds later, gets killed by the werewolf.
Answer: He must have felt he needed it for protection.
raywest ★
But why exactly? He didn't need it if he was simply going to follow his dad into the crypt.