Hildy negotiates with the Police Lieutenant to let Bruce out of jail. The Lieutenant is slow and compromised. Hildy is hot-headed and quick. This opposition in nature and attitude is what makes for a good back-and-forth dynamic between the two characters. 

Generally, it also makes for good comedy when people — like the Lieutenant — are clearly corrupted and in the wrong, yet try to wield authority over somebody who is onto them. 

Screwball comedy is a great genre to study if you’re trying to brush up on dialogue because it’s fast and coarse, much like a game of table tennis.