A day before David Preston M.D. conducted an electromyogram test on Alexis Dameron, interrogatory answers submitted on her behalf in a medical malpractice case listed Preston as a controlled expert witness, under Illinois Supreme Court Rule 213(f)(3), who would be testifying about his EMG study. Two months later, Dameron’s lawyer sent an email saying Preston was being reclassified as a Rule 201(b)(3) nontestifying consultant, and neither the test results nor Preston’s report would be shared during discovery. But a Cook …