SEMITEC interview questions

Got an interview opportunity through an agency and chatted for 40 minutes on Zoom. Before the interview, he said, "Don't be nervous, just want to understand your character, and won't talk about some uncomfortable questions." Then the third question asked me "What is the biggest mistake you make at work? " Because when another manager asked me about my weaknesses, I said indirectly, "I think the details determine success or failure, so if I make a mistake, I will blame myself for not being thoughtful." So for the "the mistake made", I said, I haven't made a big mistake, but I missed something when I first joined the company, and then I explained it roughly. But from his expression, I could see that he felt that I had not answered the question. Do I have to answer "I messed up one thing" so he can be happy? Also, did he forget what he said and what I answered?

It was a usual interview where the HR asked the most frequent questions. There were plenty of question about what you like about Japan, what you don't like, what's your religion and how well you think Japan is a suitable country for you