Try creating a detail report by payroll item (TIL Accrued & TIL Taken) and then filter it to that employee and you might find it, it also depends whether you have given TIL a $ value rather than try to follow just the hours. I have found that if any amendment is needed then you amend the employee card prior to doing the payroll otherwise the payslip will show the incorrect amount until the next pay run. Though you are probably right and it has been altered on the employee card.
I find that when employee liabilities go wrong for whatever reason it is nearly impossible (or takes forever) to try and find where and what went wrong. I have created a employee spreadsheet that works on an hourly accrual for both annual and sick leave with also columns for TIL. At least that way I can recreate accurately any liability that has stuffed up. If you want it then you can call me on 0266834083