Originally Posted by
DrakeFish
Maybe because if it wasn't an executable file it wouldn't be executable.
On topic:
I'm not exactly aware of what's up with the diablo 3 Warden, but the WoW Warden hasn't been scanning external processes for a few years now mainly because, as stated in that post about The Governor, some guy decided to alert everyone about a non-existent threat. If the current Diablo 3 Warden also respects these "rules", then you should not have to worry about tools that don't touch your game's process in any other way than reading from it. If the program injects code of any kind in the game (even if this code "doesn't modify the game's code"), it will most likely be detectable by the current Warden implementation. Now Warden protection could be implemented, but we've seen good protections getting circumvented in the past (think about LuaNinja).
ps. What I mean by detectable here is that it may not be detected, but that it could possibly eventually become detected.