I'd heard of this movie before and had to check it out - the scene I watched where he was speaking to who I assume is the female lead sounded like an American and an Italian both speaking perfectly passable Esperanto. If I were to nitpick his i's were a little soft - Esperanto i's are canonically pronounced ee - but Esperanto was made to accommodate lots of different accents without losing comprehensibility and it did that here. I actually found his Esperanto easier to follow than the girl's, but that's probably because I learned Esperanto from people speaking it with Canadian accents.