For info, the spoiler from the wreckage is the left hand inboard spoiler.
I think you're right. The following photos show it perhaps a bit better. The first is from an identical model also in Air France service, F-GZCG (and you can see the same 3 - 1 - 3 distribution of rivets in the centre, which I presume will be the same on the crash a/c):
Photos: Airbus A330-203 Aircraft Pictures | !!!!!!!!!!!!!!
This one, in TAM service, shows the narrowing & curvature at the rear corner:
Photos: Airbus A330-223 Aircraft Pictures | !!!!!!!!!!!!!!
Contrast it with this from F-GZCC on the right side:
Photos: Airbus A330-203 Aircraft Pictures | !!!!!!!!!!!!!!
And for an overhead shot:
Photos: Airbus A330-203 Aircraft Pictures | !!!!!!!!!!!!!!