As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR RETURN DUE TO LOSS OF AIRSPEED INDICATION, MACH TRIM, STAB TRIM AND STALL FAIL MESSAGES ON FIRST OFFICERS SIDE. FOUND OXYGEN SERVICE PANEL OPEN BLOCKING AIRFLOW TO RIGHT PITOT HEAD, CAUSING BAD DATA TO ADC. CLOSED DOOR IAW CL-65 AMM 12-16-35.