Then again, it could be complex depending on how they did it.
For example... let's say the line a character has to say takes about 1 minute to complete.
They could section each part off so that certain replies can occur at different points in that discussion, say reply 1 is possible within the first 15 second, reply 2 second, etc.
The longer you wait to jump in, the less... or more options you'd have.
Hope that made sense. It sounded better in my head.