Nobody's perfect. But making excuses for a mistake is unforgivable.
Mistakes are inevitable. When you make a mistake, correct it fast and put the correction in a visible place. Don't hide it like newspapers do, in tiny type next to the girdle ads.
I made at least one mistake here: Major General Buckman, Urban Legend
And corrected it on the original and here: More on Major General Buckman
Now I have some more digging to do.