At the risk of turning this into yet another FS2 intro Orion debate, upon watching the movie for some two hundredth time, I saw something that I had not noticed before. Just after the Medusa is destroyed and the camera cuts back behind them, you can see the other side of the Orion for about half a second. Here is what it reveals:

The nameplate text is quite unreadable, but the only ships in the game with the nametags were the Galatea and the Bastion, so it must be one of those. (although then again, there is the Galatea in the Colossus movie

) I could be wrong here, but I think that the Bastion was in a different system at this time, so that only leaves one choice.
I suspect the only reason that nobody noticed this before is that the viewer's attention is probably focused on the Medusas and the Dragons, which is where all the action is at the time.
Anyway, any thoughts on this?