It's not a repayment; it's a rollover.

There is no Form 5498 for 401(k) activity. They should be able to prove the rollover is to the same plan, for a qualified date, and the amount rolled minus what was held out by the person and withheld as taxes. And this assumes all of the withdrawal would have been taxable, to be a qualified rollover.

401(k) rules are different than IRA rules. A hardship distribution would not qualify for this activity.