If he is claiming them this year then he does get it. And you don't have to pay it back. It is really based on 2021. The IRS just used 2020 returns to send the checks out fast. This is a common situation. It is a IRS loophole.
See Question 15 here
2021 Recovery Rebate Credit — Topic E: Calculating the 2021 Recovery Rebate Credit | Internal Revenu...
