I’m assuming you meant to type that you had a buyer leave negative feedback. Sellers can’t leave negatives.
The buyer can’t revise the feedback anymore under the grounds that a buyer can only revise a feedback if the seller sent them a revision request, and only one revision request is allowed per feedback. Also because of the fact that positive feedbacks cannot be revised, and the buyer ended up leaving you a positive. The only thing that can happen is that eBay can remove it if the comment violates eBay policy and you report it. Like for instance if the comment has profanity in it.
