'dang may have pinned the comment to the top to make clear that he had changed the submitted title to the tweet and be open that he had done so. From what I've observed, pinning comments in this case isn't uncommon.

Edit to add: as 'Nicksil kindly pointed out, 'dang made clear he didn't do this in this case.

>'dang may have pinned the comment to the top to make clear that he had changed the submitted title to the tweet and be open that he had done so.

But he hadn't as was said in this very thread:

https://news.ycombinator.com/item?id=27401409

Ah, cheers! I stand corrected.