Confusion over IRR calculation

I got an interview question on IRR calculation:

Let's say hypothetically, shareholder A holds 40% stake in the company and is trying to acquire the remaining 60% stake from the public shareholders. The transaction is structured in a way that the company pays out a special dividend to the public shareholders (shareholder A surrender the right to receive the dividend) and shareholder A get a bridge loan to pay for the rest of the consideration. Post-transaction, the company will pay dividend to shareholder A to repay the bridge loan and the accrued interest. The question in this case is how do we calculate shareholder A's IRR given shareholder A didn't really pay out any cash in this scenario?

My answer on the spot was that we need to factor in the forfeited dividend into the IRR calculation. My interviewer said that it should be the rollover equity instead.

Is rollover equity the correct answer? If so, why is that?

Thanks.