There is a situation which allows loading of a recently expired puzzle. I'm wondering how this might effect scoring data on the server if the puzzle is actually played and the score is increased.

The situation arises thus:
A puzzle is played before it expires (eg:120 Grand Challenge 4) then the client is closed. While the client is closed, puzzle 120 expires. Upon the next client login, from the Main Menu, one can select "Continue in 120:Grand Challenge 4", which has now expired. One can then play the expired puzzle.