Spot on. Firing someone for a mistake is incredibly short-sighted. After the mistake has been rectified, you can be sure there is going to be one employee in the organisation who will never ever let that problem happen again. Why do you want to get rid of that person?
Of course, if the person is making the same mistake again, then that may be reason for concern, but that's a completely different discussion
Of course, if the person is making the same mistake again, then that may be reason for concern, but that's a completely different discussion