[Retros] determined=finished if mate. Only in America?

[raosorio at fibertel.com.ar]

Hi,
I finally found a retroproblem I was looking for, connected to the MDR area
(fractional moves).

It's P1012842 in the PDB, by Bruno Sommer, a very interesting composer who worked
intesively the retrojustified fractional moves.

the position is,
Bruno Oswald Sommer
Funkschach 1927
2b5/pp1pp2P/6pR/2K5/1P4PR/P4P2/p2PP1PB/3N1Brk

The very good retroanalysis shows that the capture Bh2xRb8 is underway, where the rook
has already been removed from the board and to place the bishop on b8 is still pending.
So, the mate is determined. But, the problem was presented as  #0. Why 0 instead of 0.5?

This is in 1927 and not in USA, where Gianni teached us the local Code establishes that
"a move is finished when it's determined (irreversible fraction) if it delivers mate", so, to
deliver mate you don't need to complete the move?!

First  20th Century half . An example of american cultural penetrarion?

Roberto