Where's the alien?

Rating: Null/10 (12 July 2004)

In the beginning scene, where the one alien is hit by the Professor's assistant still being into the secret room, the wall is starting to move and closes before the alien is able to escape. - It's hand is left between the two halves of the wall.
When Korben, Leeloo and Cornelius & David return to this room in the end of the film to put the stones at their places - where has the alien gone to? As it is big and mostly made of metal, there should at least be some parts left, shouldn't they?
By the way: Those Alien just look CUTE! :))