The cameras are there to purposely capture the image of someone else stealing the orb.

In other words, yes... the Arsenius group.

A hastily opened museum full of imitation dinosaurs... They must have noticed that it was a trap...

As a result, you've successfully provoked a group of theatrical serial larcenists.

Of course, you weren't going to let the orb be taken so easily. So in order to take it back later...

You'd planted a tracking device inside the orb's pedestal.