"I mean, Danny Boyle, if you've met him, is like the world's nicest guy," Ahmed said of the director of the Oscar-winning movie.
"He made me audition for the role that Dev [Patel] ended up playing so wonderfully well, and he was like, 'You're not right for that. Play his brother,' who's got a bit more edge. He's a bit of a rough kind of guy, this character."
Ahmed said Boyle gave him free reign to embrace the aggressiveness of his character and gave him permission to "get up in his face."
"Before you know it, I've got Danny up against the wall, I'm like screaming in his face, spitting in his face, I like ripped his shirt," Ahmed recalled. "I ripped the seams of his shirt open, and I was spitting into Danny Boyle's naked chest."
Ahmed said Boyle calmly cut the scene and thanked him for stopping by.
"I walked out of that audition thinking, 'I nailed that,'" he said to Moss, who could not stop laughing.
Boyle clearly didn't think so because the part of Salim Malik ended up going to Madhur Mittal, who later took home the Screen Actors Guild Award for Outstanding Performance by a Cast in a Motion Picture.