Can a party holdback evidence from an Initial Disclosure?  In Arizona, if I’m understanding the rules of procedure correctly, each party has 40 days (is that accurate?) to make their initial disclosure to the other party from the date that the Defendant files their initial Answer to the Complaint. My question is, can a party for whatever reason hold back certain documents of evidence from the initial disclosure and disclose them to the other party in a future disclosure (so as to surprise them in an advantageous way), or must a party disclose EVERYTHING they have at the time the initial disclosure is due to the other side? Is there any real way to know if a party is holding documents back, it would seem hard to prove?