How you react when your friend messes up tells everybody whether it’s safe to mess up around you.

Your reaction sets the temperature for the whole group. When a friend admits a mistake and meets ridicule, everyone present learns to hide theirs, and the next problem surfaces much later and much larger. When they meet a steady response, honesty becomes cheap enough to afford. You are writing the rules without anyone discussing them.

Next time someone tells you they messed up, say thanks for telling me before you say anything else. Deal with the problem after you have dealt with the person. Ten seconds there decides what people bring you for years.