Only some lines of a transferred asset were actually transferred to GL - is this a bug or did we mis

We're on 11.5.10.2.

In our corporate book, we have an asset with 10 units that had a total cost of 10,030.49. The asset was assigned to an employee. The asset was fully depreciated in NOV-05. The employee is no longer with the company so in MAR-09 a transfer transaction was entered to unassign the asset from the employee; however the user keyed -1 units instead of -10 using an accounting date of 01-JAN-2009. A problem was discovered where not all the lines transferred to GL. Yesterday, in our recently cloned instance the user unassigned the other 9 units from the employee hoping it