Never happened before. And for 1 member to lose 10,000 posts, that's one hell of a lot of deleting, blanket deletes without a care to the content. I've noticed that it's not just me, countless users have suddenly lost 5K posts etc.
We will look into it. If your post count or number of Likes has changed, it's most likely due to an indexing problem. The posts are still there, and the total should be corrected soon.