How about "Whoa!"? That seems to me like it preserves some of the ambiguous sense (calling for attention vs. remarking upon a discovery).
The issue is really focused on the grammatical function of the word. The researcher is arguing that it's not ever used as an interjection, which "whoa" always is.
The issue is really focused on the grammatical function of the word. The researcher is arguing that it's not ever used as an interjection, which "whoa" always is.