Notice to Buyer to Perform Cans and Can'ts

[Yeng Hawj]

I currently have my house in escrow with a buyer that has been a headache to deal with.  Escrow has not closed when it should have, and buyer has not returned all of the required docs, and has not released any contingencies.  My agent sent over to the buyer's agent a C.A.R. Notice to Buyer to Perform to release all contingencies, return all of the docs, including 2 addendums.  One of the addendum is an AS-IS disclosure.  The buyer's agent is saying that because the NBP has the addendums attached to them, the NBP is invalid and voided.  Is that true?  TIA