My mistake or yours?

Yesterday I was telling that it takes a lot of balls to say “my part is clean. the mistake must be in your part”. He countered saying the opposite. That it takes a lot of balls to admit a mistake!

My argument is that if I know it’s my mistake, it is easier for me to say since I’m 100% sure that the mistake is in my part, and I also have control over it to correct it!

By saying that the mistake is not in my portion, I’m saying it with a certain confidence bound, and I can’t give a 100% guarantee that I’m clean. Also, in a way, I’m accusing you of making a mistake! And there’s the danger of falling flat on my face if it turns out that the mistake was indeed in my part!