After reading your blog : I would say : interview depend totally on candidate on how he/she wants to drive, its never like an QnA, unless you are giving a HR round. its like : you say something : other person asks more about it : you explain more. and this is how an interview is driven.

The feeling you expressed is a true feeling of a candidate after the interview : but you are thinking that you did everything best : I would suggest to think from interviewer's shoes as well : how you gave interview : if you are someone taking interview : and candidate gave this responses : would you hire him or not

if not then what could he/she do better...

Reflect like this...