Why does De Niro have a director credit on Netflix?

On The Score's page on Netflix, both Frank Oz and Robert De Niro are credited as directors. I assume this is a mistake since I've never heard of De Niro having any significant part of directing the film. In the IMDB trivia there is this:

Marlon Brando took to calling director Frank Oz "Fozzy" and "Miss Piggy" during the movie. Oz is the voice of the Fozzy Bear and Miss Piggy characters in The Muppets. Brando's hazing of Oz over his work with the Muppets got so bad that Robert De Niro was forced to direct Brando instead, with Oz giving him instructions via headset.

Though, that doesn't seem like enough to credit him, and he wasn't officially credited.

¡Viva Machete!