MySQL Error: Duplicate Entry on indexing taxonomy structure with Search API Problem

I have a search index. I use a views page with this to create a search page and results for users.

I was forced to re-create my search index. I deleted the old one and I'm getting the following error when I attempt to index the new one after re-creating it.

(Technically I get 49 errors, one for each piece of content i'm trying to re-index)

SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '632' for key 'PRIMARY'

I only get this error if I attempt to index the hierarchy of a particular taxonomy field. 

It sounds like it's trying to re-generate the ID for my set of items, but even uninstalling and re-installing the module and re-creating everything doesn't clear the error.

Any ideas about what might be causing it? Or what I should look for in MySQL as I dig through tables?
I raised an issue in the Search API queue which then got patched. Forgot to post about it here. My bad.

https://www.drupal.org/node/2174163