Condo sale without condo knowing

how is that possible?

I wouldn't want to live in a condo where the condo board/management is clueless of whats going on.

I'm with AB - how do the lawyers do the closing without the RFR waiver?

Yes, should be a provision in the contract that stipulates this as a requirement. Could be that the contract is invalid as a necessary condition was not fulfilled.

I think the question here is how does the condo association retroactively exercise its leverage once a sale has been completed by the parties (and probably recorded). Presumably the seller and buyer aren't looking to reverse the transaction, and the condo is not a direct party to the sale contract, so those terms don't provide any leverage. Assume the condo declaration and/or bylaws provide that a non-conforming sale is an invalid one. But what next?

Is it a lien on the unit? A lawsuit against seller and buyer seeking to roll back the transaction as invalid? A filing with the county clerk attempting to impugn the recorded transfer? Eviction proceedings against the buyer on the basis that they don't actually own the place?