Gaffes

After attacking Ivy in her room, Jekyll runs away from her house. As he approaches a carriage, his hat flies off and he keeps running around a corner. In the next shot, from the other end of the corner, his hat is securely on his head.

Ivy knocks Mr Hyde's bottle of champagne off the table, but later he lifts it from the table to smash over a man's head.

In the fight with Sir Charles Emery, Hyde loses his hat. In the next instant it's back on.

When Lanyon takes the broken cane and examines it, he turns it so that the broken end faces up. In the next shot, the curved end faces up.

Tracy carries Ingrid into her apartment, when they first meet and she feigns injury. He has his hat on. After they kiss and he exits, he has left his hat inside, but in the carriage with his friend, his hat is back on his head.

When Jekyll and Lanyon drop off Ivy at her home, a wire is visibly attached to Ivy. It evidently helps her as she falls out of the carriage and, again, supports her weight as Jekyll carries her inside.

Spencer Tracy's double is very obvious at various times in the movie.

For part of the scene in the music hall, when Hyde is talking with Ivy, it is dead silent with no background sounds at all.

Spencer Tracy's real teeth are readily visible behind his fake Hyde teeth in the closeup scene with Ivy (towards the end of the movie).

It does not make sense how Ivy does not recognize Hyde when he looks almost exactly the same as Jekyll.

Right after Marcia and Ivy have been talking about a new theatre production and Hyde enters the room, the shadow of a boom mic is visible throughout much of the remaining scene with Hyde eating the grapes and playing the piano. The mic shadow, visible on the back wall, moves over to the doorway as Hyde enters, interrupting Ivy and Marcia, and follows him around the room. It's quite visible.

At the very end when confronted by his friend and the police Jekyll says "I'm Doctor Henry Jekyll" but in this movie his name is Harry (Henry is the original name in the novel).