My Experience: Failed Google interview

Hey all, just wanted to add here about the first interview round that I had with Google. I can't disclose the exact question but it was a Topological Sort Graph based problem (something like Course Schedule on Leetcode). I almost got the approach right but there was a bug in my code and not enough time to solve it. I solved approx 150 Leetcode problems before the interview (except DP). I am a bit disappointed since the interviewer mentioned at the end of my interview that my code seems fine but there is a bug and we have to stop since we are out of time, but the recruiter called me a day later and said that I got "Below Average" rating in most categories like Coding, debugging, etc. This is confusing me a bit as I have two different reviews. The code I wrote was the optimal solution (with a bug) and I verified it on Leetcode too. I am not sure how objective interviewers are at Google (or big tech) in their evaluation as I felt that my code was not bad at all. This is not to say that my interviewer or recruiter were bad, they were actually pretty great and friendly. Please let me know what your interview experience has been in big tech since this was my first time, and how much luck is involved, interviewer's mood, etc matter here.