Must have been some sort of update via stream Hope can get sorted soon.
Yes, you're right, the new free dlc + 2 or 3 small updates/fixes that changed the version of the executable
But SP G 2 is still version 1,5000!
The Starpointgemini2.exe "Details" tab in the "Properties" do not give any numbers as "File version", the "Date modified" clearly says: 14/06/2015 6:09 AM.
But yeah, in-game "1.5000 DLC" is the version given.