If we suspected this was happening systematically in a project, we would immediately remove it from the whitelist until the project administrators demonstrated more robust security. It is definitely within the power of administrators to do this; there are BOINC threads out there discussing exactly this issue. Don't forget that even without Gridcoin, people like to compete using credits. So the BOINC community has invested a fair amount into ensuring accurate distribution of credit.
Don't forget also that you can't choose which workunits to download. So you'd have to sift through the automatically downloaded workunits until you finally received one you'd done before through a different client. This would be pretty tedious.
O no, what i mean was that those were downloaded in the same batch, it is a very limited bug but it can have a long term impact if incorrect data (this ryzen cpu is relatively new, it could had a undiscovered cpu bug) . But it isnt that serious as i impulsively thought.
Oh, sorry, I misunderstood. My bad. So it does sound like a fairly localized problem that can be fixed within the context of the project. Good someone is noticing, because yeah technically speaking a bad result could inadvertently be passed.