well lets get things straight. You bought some forks, used them and they broke. You initially said that you had a soft landing so you will agree that the forks have experienced some trauma.
SRAM say that they will not honour the warranty as they have been crashed. Or experienced trauma.
The first thing I would say is that forks should be designed to experience a certain level of trauma. So the question relates to just how much trauma your forks have experienced and whether the forks should have withstood this.
Incidentally do you still have these forks in your position?
So the first thing we must do is establish whether there are any other physical sighs of crash to the fork. Gashes, missing paint dents etc? if your answer is yes then it could be reasonable to say that they have been crashed. If the answer is no, we probably cant blame the damage on a crash and perhaps should look deeper. Again if the answer to this question is no than there is no way that SRAM can categorically say that your forks have been crashed.
I would say that in general your forks will not have been looked at someone who knows much about the materials and the processes employed. I would guess that they are some customer service guy or rep whose default response is to refuse. (I generally find that people who work for bike companies are not that clued up). Anyway, its unlikely that they will have been looked at by a metallurgist and a failure investigation done. Particularly if the forks are still in your possession.
So whats next. if there are no other marks on the fork, we will never know the level of trauma the forks have seen. So we have to look at something else. We should investigate the materials. This will involve looking at the two fracture surfaces in some detail.
So the question is has this been done?