I believe it goes something like "sometimes you win, sometimes you learn". The ends are important, but they do not justify the means. In this case, if the means are you did your best at the time with what you knew at the time, you did good. It's all you can do. Don't worry about what you can't control. Criticism is free growth - no need to attach a price to it by taking things personally. As to how, just remember how you feel when you bring something up to your manager, or a senior executive, or another engineer - you mean well. So do they.