Each team quantify downforce "points" differently - it's an arbitrary scale each team decides for their own internal use. To memory, Macca says every point of downforce is half a tenth (0.05 seconds).
In said context, 10/12.5 points of downforce seems a bit excessive. Was that just a random, arbitrary number to illustrate your point, perhaps?
EDIT: I'm talking rubbish. A "point" is talking in terms of cl, where 1 added point is 0.01 more in terms of cl.
Try looking here:
viewtopic.php?f=6&t=8250
Q: Jenson Button has suggested you were ‘30 points’ behind Red Bull in terms of downforce and that it would take six or seven races to make up that deficit. Do you agree with that analysis and can you explain what ‘30 points’ means?
Paddy Lowe: A point is Formula One code for a hundredth of a fraction of ‘cl’, where ‘cl’ is the downforce coefficient. Physically a Formula One car has a downforce coefficient of let’s say 3 to 3.5. So 30 points would be 30 hundredths which would equate to 0.3. So 30 points might be getting on for 10 percent of the downforce on an F1 car and that could be worth about a second a lap.