"Medvěd honí nás! " is incorrect?
It is very strange.
"Ten medvěd honí nás!" is possible for "The bear is chasing US!" when you say he is chasing US and not something else, but for "a bear" it is really strange.
So to think about this in other contexts - that which is adjacent to the exclamation point, is by position, stressed?
The last word in a sentence is normally stressed - it is the new information, the so called comment or focus https://en.wikipedia.org/wiki/Topic_and_comment