Much will depend on the quality of selection & training of CA's.
Questions raised.
First, assuming the reports are correct: Captain makes reassuring announcement that all is OK. Cabin crew open door without command. Why?
Pax exits before slide inflates, assuming it was armed. Wow, that was fast. Pax must have been in aisle of 1st 3 rows, at a guess. Did the pax demand the doors be opened and CA's panic?
To open a B737 door the CA is 'in' the exit. If the pax was in a panic dive before the slide was inflated I'd have thought they would have taken the CA with them.
Many aspects of this, as reported, seem very strange. The lawyers will have a real dilemma where to start. Who shall be the target? The airline will then counter sue. The film should be an interesting story.