Inventive Defendant urges Westerners to invest in his new invention, the "Phone Head," a device that attaches your phone to the side of your head for hands free driving. After some 500 California and Nevada citizens do just that, several lawsuits are filed against Inventive by persons who have purchased the Phone Head. The lawsuits allege that the plaintiffs have developed severe and debilitating neck and back injuries due to the prolonged tilting of the head required to use the device while driving. Whitney sues Inventive in Nevada state court for the $100,000 she invested. Inventive seeks to depose Whitney, "to learn why she and her lawyer have filed this lawsuit." Whitney does not attend the deposition on the day it was set by Inventive, and the Nevada state court therefore dismisses Whitney's lawsuit "with prejudice." Whitney then appeals to the Nevada Supreme Court. While Whitney's appeal to the Nevada Supreme Court is pending, Whitney's attorney-newly graduated from the University of Aruba Law School-files the same claim against Inventive in the federal district court for the District of California. She brings this action "on behalf of all California and Nevada citizens who were defrauded by Inventive's scheme." Although she is the only named plaintiff in the lawsuit, her complaint alleges that "whether the 100s of citizens of California and Nevada lost $100,000 (as I did) or $100 (as many others did), we all are entitled to monetary relief." The court denies Whitney's motion to certify her action as a class action. Whitney's individual claim therefore proceeds to a jury trial. Whitney testifies about her investment in Inventive's company and then rests her case. Inventive then testifies and also attempts to call an expert on head gear. Whitney's attorney objects that "we have never heard of this person," and the judge refuses to permit the expert to testify. At the conclusion of all the evidence, Inventive moves for judgment as a matter of law. The trial judge states, "I am going to grant this motion because Inventive is a much move believable witness than Whitney." For the purposes of the following questions, presume that the state procedural rules and statutes in California and Nevada are identical to those of the federal courts.

Then please answer the following questions in IRAC format

1) Could Inventive have used the Nevada state court judgment to assert claim or issue preclusion in the final California federal lawsuit?

2. Assuming that there was federal subject matter jurisdiction to hear the case, should the California federal court have certified a class action in the final lawsuit?

3. Was the California federal judge correct in refusing to permit the expert to testify at trial?

4. Should the California federal judge have granted the motion for judgment as a matter of law?