Flipped

I did a coderpad based technical round where I was asked a leetcode hard and then follow up for that, did the initial question and realized that the following up was a combination of 2 leetcode hard, luckily had done the same question a few days before and kind of remembered the solution/approach. Told the guy how I would go on with the solution and how to implement it and how it is optimal and better time complexity, and he kept on saying that I am wrong and it won't work and the time complexity is not right, even after explaining the whole solution a couple of times. At the end of the interview he said that I am wrong and lets agree to disagree, to which I said I was not and he should look it up. I looked up the solution after the interview and I was right. I am screwed right? PS: I also found the guy on LinkedIn and have been thinking about sending the screenshot of the leetcode solution to him, a bad idea right?