Honestly, we generally don't touch records of any user unless something warrants it. I don't recall us really modifying any users' records just for the sake of it. At most, we've added other records to counter the mathematical score, but the actual records stay there. (e.g. You can have a Score of 0, but have 2 records on file, one positive, one negative. They cancel each other out to give the 0 score.) Well, there is the occasion were we need to delete mistakes (like double records), but that another issue.

My advice? If you really want that -1 to disappear, contribute to the site in a meaningful way to the point someone decides to add a positive record for you. Speaking of which, looking at your user history, you're getting there. Someone may decide to give you a record for prolific tagging, something the site needs to improve search results.

Really though, records don't mean much unless you're a repeat offender. Unfortunately, neutral records don't exist in the system for use. You seem to have gotten a warning, which are good cases for neutral records. But that's a different topic...