Comment by guessmyname

It was clear from the very beginning that the decision was more on the "culture fit" side than the knowledge. His attitude shows this and then is confirmed after he quit Apple (who hired him no long after Google's rejection) and he — himself — stated in a message via Twitter that Apple's work environment was not for him.

Reversing a binary tree is not that difficult, and a good interviewer (specially the ones at Google) already know this, but if the interviewee shows an angry face out of frustration and doesn't ask for help or doesn't communicates his inability to proceed with such task, then what does the interviewer says? Rejection!

Interviewers also evaluate your communication skills.