Because I thought he'd gunked my game.
3 seconds sound clip from the After the Thin Man (1936) movie soundboard.
You can hear this line at 01:42:23 in the DVD version of the movie.
Quote context
[...]
- What kind of a stumblebum does that make me out to be?
- Then why did you go to his place?
- Because I thought he'd gunked my game.
- I figured he'd tried to hold up Landis and had to kill him...
- So I pushed him around a little just to learn him manners.
[...]