Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Situational Awareness
Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Passenger Electronic Device
Flight Crew Overcame Equipment Problem; General Flight Cancelled / Delayed
Human Factors
After block out; a passenger advised our lead flight attendant that she had loose lithium batteries for her laptop in her carry on bag that had to be gate checked at the last minute. After advising ZZZ operations via the radio; the decision was made to retrieve the bag from the cargo bin so the passenger could retrieve the batteries. I opened the cockpit window and advised the gate agent to pull the jet bridge back up to the aircraft. I then advised the Lead Flight Attendant to disarm all doors and that they were pulling the jet bridge back up. In the process of disarming doors; the gate agent somehow managed to open the L1 door before the Lead Flight Attendant could get it disarmed. Being an Airbus; the door disarms automatically when opened from the outside so luckily no one was injured. Increased training and awareness for gate agents on the visual cues on the Airbus that shows that a door is armed prior to opening it.
Airline Captain reported being notified passenger had gate checked carry-on bag containing loose Lithium Ion batteries. Jet bridge recalled to retrieve bag.