Question regarding the timing of Costs returned when an RMA is processed

We had an RMA that was for 12/27/18 that was processed with a return date of 12/27/18 and receipt dates on the lines for 12/27/18. It was RMA’d on 1/2/19 and "RMA disposition"ed that same day.

It looks like the parttran table gets the date of 1/2/19 for all of the return transactions, and while the revenue transactions and credit memos all seem to show the 12/27 date, the inventory and cost of goods sold credit transactions were dated 1/2/19 and crossed our year end. Yikes!

We fixed this we think with adjustments (I am not the accountant! IT here) but I am curious if we transacted this in a way that caused this issue or if this is business as usual if you cross a month end period with an RMA.