Though unusual, omitting sawteeth from the Randall #18 knife is seen occasionally. It is a special order ("STNST"). Here's a picture of mine:
https://www.dropbox.com/s/u8sl7iihb4...-NST-.jpg?dl=0
In my opinion, this knife is more attractive than the sawtooth version. In any case, I don't expect to have to saw my way out of a helicopter!
-Steve