Something I can never understand with my boss. This really makes me concerned with the future of the company imo.

I was given a project contract with all of the specifications and how many hours I had to each assignment.

I did my work and I kept myself within the time limit.

Today my boss and I had a status meeting about the project. In which he had an addition to one of my features which would basically require us to start over with it. He started to blame not only me but also my coworker on why we didnt predict that HE would want this addition to the feature. We got into a heated discussion over him putting that blame on us. My point I stuck to, was that the responsibility of specifications lies in the person who briefs a worker, not the worker who is supposed to play guessing game of what the briefer want. He vehemently denied that is how things work.

He basically shushed me and said that is how the order of things go.

Am I in the wrong here?