Difficulty: Moderately Challenging
Step1
Apologize and try to fix the mistake if you recognize you caused a problem. That will demonstrate your good will and will defuse anger or resentment on the part of your coworkers.
Step2
Avoid confusing the message with how it's delivered. Susan might not put the issue to you in the best way possible, but you should remain calm and deal with the essential problem. This will calm things down and make it easier to communicate.
Step3
It's hard not to get defensive, but at least try. If you did, indeed, mess up, admit it. Apologize and offer a reason, not an excuse for the problem.
Step4
Try to find a resolution rather than simply hearing the person out. For instance, say that in the future you'll add in some extra time to lessen the chance of missing an important deadline.