I am very disappointed with the pair programming result.

I was told by the recruiter that I didn't get the solutions to work, but that was a totally incorrect statement.

Where is the integrity here?

I signed an NDA, so I won't share the details. Before pair programming, I shared my proposal with the interviewer. He agreed and said I should go ahead with it. But apparently, he wasn't comfortable with my approach later on. I got the solution to work, but I was told that my solution was not working. There was nothing I could do to argue other than telling the recruiter that their statement was incorrect. I understand it's hard to remain objective during the interview process.