If your code offers an expectation of determinism then it's sloppy to not distinguish where there isn't determinism. There's nothing difficult about writing a comment to the effect of "this function is non-deterministic. For deterministic results, use X".

The code is sloppy if the developers didn't consider determinism and offer nothing to consumers, or if the consumers writing software cannot know where non-determinism is introduced.

If that's somehow insulting then I'd say someone has very thin skin.