What do you do when somebody blasts you on their blog??
The first thing that happened was all the blood in my body rushed to my head.
I got angry.
Then, the doubts came.  Did I really make those mistakes while writing a pattern? 
Next thing, I pulled out some yarn, needles and feverishly started re-knitting said pattern.  Well, I didn't find any mistakes.  Plus, 14 other knitters have knitted my pattern and I didn't get any error-feedback.
So, what do you do?  
I vented with my husband.  Poor thing.  He loves me, I know and is willing to put up with me.
Now, knowing that the pattern is fine,  I'm moving on.  But not after I wrote a comment on the perpetrator's, I mean,  the knitter's blog.  I was nice. I wasn't rude. Who knows.  She might become one of my best friends yet.