I've watched the NHTSA video of the side impact test over and over, and I'm not seeing where the door came open. The video shows the entire collision, up to the point where both the sled and the smart are stationary, and the driver's door appears to remain completely closed at all times.
It may have come unlatched - it's not possible to tell from the video - but the statement that it "unlatched and opened" seems misleading based on the footage. Do they mean "unlatched and therefore could have opened"?
The car is spun clockwise after the impact, which would tend to make the driver's door fly open if it were unlatched. And yet the video shows no such thing. Just saying something seems a bit off to me...