This man appears on rolls 'Absent, on detail at Div Hqrs' for the roll dated April 30, 1864. Evidently he deserted after that date and prior to the roll dated at the end of August 1864. However, I agree with your statement that "the actual date for the first payment is more likely to be 19 November 1863." You will find occasional clerical errors like this. Whenever a War Department clerk recognized an obvious error on an original document, he marked the item with an 'X' and wrote, "So on roll."