Yet another one! Dunno why it's such a trend for twins to have their doors popping open in flight for videos but not much different of a problem than in Mooneys. Kuddos to the pilot admitting it was his mistake/responsibility for not checking the door was properly closed before takeoff and making a safe landing. Dave Hirschman, AOPA Pilot Editor at Large, narrates "as pilot in command, this was my fault. I failed to ensure the Baron's passenger door was closed and locked before takeoff so it popped open in cruise."
There is definitely a pattern of complacency across these videos and similar stories of the pilot in command failing to perform proper preflight action and pretakeoff checklist to ensure the door is properly closed. Too much trust in the passenger being able to close the door. But, worse yet, it makes you wonder what other pre-takeoff items they may be skipping if they are not checking the door per the checklist?