The sentence is
I would have understand them if it's not the for the "突然" part.
- (1) "Suddenly father exhaled (once)" (like "ooooh" and then maybe died).
- (2) "Suddenly father started to perform an exhale." (and after he performed it maybe he died).
P.S. Sentence (2) As far as I see doesn't have niether of those readings:
- Conteractual. "If something happens/ed, then he has/would exhaled.
- Suprise. He can exhale?!
- Probable. Well, he can exhale.
- Future. He might exhale.
- Deductive. He exhale. (I can say that based on some reasoning)
- Abilitive. He can exhale.
that 突然 eliminate all those readings and I'm lost a bit.