Ethical issues in law

1.You are a LNC working for a criminal defense attorney. The case
that you are working on involves defending a local physician who is alleged to
have been diluting and adulterating medications before selling them directly to
his patients. Agents of the Drug Enforcement Administration videotaped the
doctor while he was diluting medications in his office after the close of
business. This videotape is the best evidence against the defendant doctor who
your supervising attorney is representing.

Before a pretrial hearing you observe a nurse
employee of the defendant doctor approach the federal prosecuting attorney and
talk with her in the parking lot outside of the local courthouse. The
prosecutor happens to be holding the videotape and some other papers in her
hand. You observe the nurse pull what appears to be a large magnet from her
oversized purse and lean toward the videotape. You know that if the magnet
makes contact with the videotape, it will erase the contents of the videotape.

As the LNC working for the defense of the doctor,
what ethically should you do, if anything?