The answer provided is correct. To work out exactly what the deduction from your wife's pension should be, download Schedule J from the State of Hawaii taxation website.
Schedule J requires that you work out what your total employer match was. The good news is that even when you roll over to a new account (from a 401k to an IRA on retirement, for example), the funds retain their identity as an employer match. Those funds (and anything they earn) are exempt from Hawaii tax.
Sched J, however, is a bit of a pain. You have to go back through your records. As I was working on it, it became clear that I wasn't going to save much by subjecting myself to that agony, so I just set the deduction to zero.
