From what I know the levels and models in that release are from 6 months ago.. and from E3..
Why would they carry around completed hl2 levels with them to show off 6 tech demos..
I'm guessing the other maps were there as backups incase people weren't taking any notice. I don't think the seabed one in the buggy was meant to be shown at e3 (I base that assumption on the filename though).
So in summary I belive the exe and the dlls are up to date but the levels are old.
There's no way you can belive that those 72 maps are all they've managed to achieve in 5 years.