Question Top Posters statistics is outputting phantom accounts

When you delete an user, there are sill entries created by this user in polls or thankyou. I had started making a fix for that here : github.com/xillibit/Kunena/commit/9a3091...a3e325371045cd875ee8

But where are the phantom post counts coming from?

I know in my case that those numbers cannot be sums of old polls or thank yous, because deleted users are not active enough to participate in polls or give/receive thanks.

Or to put it more simply, how can the Top Posters report be listing data from polls or Thank You?

I know the answer in here.

When user gets deleted, all of its posts are kept in the database, unchanged. That means we still keep user ids for those records.

Statistics works by counting all posts from each user and listing the top ones -- which basically means that there are a few users in your site whose accounts were removed even if they had posts written by them. In all or at least most other views these posts are identified to be written by visitors. But statistics does not check if the user exists or not, which causes these phantom records to appear.

Keeping user id in the posts is OK, as it allows users to change their minds (and us to make a tool that allows to bind posts to a new user). But phantom users in statistics should be fixed.

Here's the bug in our issue tracker:
github.com/Kunena/Kunena-2.0/issues/1619

I tried Recount Statistics from Forum tools but the problem remains.

Is there any way to fetch the right statistics?