How could I know, Eivol?

4 seconds sound clip from Batman (1966) - Zelda the Great (S1E9) TV Series.

You can hear this line at 00:11:16 in the Blu-ray version of the movie.

Quote context

[...]

- Oh, boy. I'll bet somewhere in Gotham City there's one really shook lady crook.

- I hope so.

- Now to make this planted story sprout.

- Meanwhile, behind the facade of this innocent-looking bookstore, there lurks the secret workshop of a strange Albanian genius... Eivol Ekdal.

- Sorry to be late, Eivol.

- Counterfeit you bring me. To me, Eivol Ekdal, worthless counterfeit. Look.

- How could I know, Eivol?

- How could I know, Eivol? (2)

- Zelda the Great. Even greater than Houdini.

- Without the marvelous escape devices which I, Eivol Ekdal made for you each here, you would be nothing.

- Stop taunting me. I've always paid you well, haven't I? I've even taken up a life of crime to pay your price.

[...]