@XPMorten,
I agree that the lower bucket hit the ground. I however believe
that this happened on the RWY during rotate!
That may be plausible. If so, it may be an indication the buckets on at least one engine were deployed before or during rotation. I see no reason to intentionally deploy reversers while also anticipating or initiating a rotation.
On the picture there are no relevant dirt marks visible on the warped bucket. It's trajectory after separating from the aircraft or engine before it came to rest may also be attributable to its damage but i would expect that the upper bucket would also have shown more signs of a beating if that was the case. It all depends on when and how the reverser detached.
It makes me wonder in which condition the reverser buckets of the other engine have been found (have not seen a shot of those buckets yet). Serial numbers will quickly reveal which reverser was installed on which engine.
Green-dot