If you try to include any invalid transaction in the proof, you will not (w.h.p.) be able to create the proof condition. So that update would be rejected. It is

If you try to include any invalid transaction in the proof, you will not (w.h.p.) be able to create the proof condition. So that update would be rejected. It is up to the proof generator to verify their transactions before including them in a proof. A proof verifier can accept or reject a proof trivially.