"Part of that rollover was taxable. They have never had to file form 8606 before"

We're going to need more details, then. Typically, nothing is taxable unless it also is converted. A Rollover from a tax deferred plan/account to a tax exempt plan/account, such as 401(k) to Roth 401(k), is taxable. Or both 401(k) and designated Roth to Roth IRA, is taxable. The types of plans/accounts matter, because there likely was supposed to be a Form 8606. Or perhaps it was some sort of ESOP? Are you sure it was "rolled" to an IRA account? There was a topic posted here last week about TSP-to-IRA, which isn't even allowed, for that taxpayer.