From accounting point of view it does make any difference, as both treatments will have same impact on balance sheet.
Taking GST into consideration which is charged on Supply and in earlier laws the tax was mostly on sale.
When one purchase goods, it is supply and at the time or purchase returns again it is supply. So I think the correct way should be to credit outward tax ledger instead of reversing input tax ledger.
But again one has to carefully account the transaction as this outward supply should not affect your revenue.
Software should be designed in such a way that correct tax details can be extracted and respective P/L ledgers do not get affected by tax adjustment entries.
For instance our habit and practice has been associating output tax with revenue, but under GST this may not be the case.