Passenger Door Will Not Open from Outside

What is your question?

I have a 1991 Toyota Celica Convertible. The passenger side door will not open from the outside. The electric lock itself will un-lock, but the handle must be pulled from the inside for the door to open. I have been told that it could be the door lock mechanism or that it could be a plastic clip broke off from the lift rod. Not too sure which or how to tell which one it is. Any advice would be greatly appreciated. Thank you.