During the initial chase scene, the cars drive by a store called "Bromley's Bargain Headquarters." Perhaps coincidentally, one of the film's stars is Sheila Bromley. (There's also a "Sheridan Haberdashery," possibly a nod to Ann Sheridan, who was a rising star at Warners at the time.)
When Dan, after punching out a gangster , gets ready with Lee to enter the room where Julie has Janet and her mom captive, Lee turns off the hallway light. But on the next cut after the gangster regains consciousness and sneaks up behind them, the hallway light is now on.