Buyer not a part of release strategy then how can he reject PR after final release?

hi Gurus,

We have below requirement from client.

we have PR release strategy and procurement team is not part of that. once final release done then PR will be release but if buyer want to reject it then how can he will reject it?

(We are using item level release.)

Procurement team wants authority to reject PR after all release.

I suggested to add new release indicator for Procurement team.

is there any other easy option to reject PR after all release

Thanks..