The interviewer speaks poor English, he had hard time expressing himself, but I think I understood most of it, since most phone interviews ask similar behavior questions. He gave me a medium difficulty coding question and I did solve it using the best time and space complexity approach, I double make sure it by Googling after the interview. So I feel confident that I will pass it. But the guy failed me, WTF?
Bad luck but that's how the interviews work currently. Cannot be sure of result even if you think you aced it. Luck is another factor in addition to your prep and skills. Same thing happened with me for Dropbox. I though I nailed it but got rejection in couple of days.
Yes, this kind of things really suck