I used to think they abandoned it, but I read somewhere that the field notes on Gabranth and Lyon were written word by word exactly the same as the how the story writer did. Meaning it was always planned for their end to be told that way.
I had found that somewhat lazy initially, but later I realized it makes the story darker - Gabranth died in a way that his body couldn't be fully recognized and we never got to see exactly what happened, giving this air of mystery.
