hmm, i'm not too good with posting puzzles, the alternate moves didnt show up, you have to click on move list.
The alternate was 1.Rxd5+ cxd5 2. Nxg6+ hxg6 3. f4#
If after 2. Nxg6+ hxg6 3. f4+ ;
the e pawn could still capture en passente.
ok, tyvm guys
I guess I should have seen in the move list the f4+ and not f4#!