Hunger Games vocabulary

The Hunger Games has generally simple vocabulary. The  book is made up of average terminology and little to no slang in narration or dialogue. There are however exceptions where the diction is more sophisticated and there are slang words. For example on page 134 " 'whats going on?' says Effie, a note of hysteria in her voice." This shows good diction and vocabulary with the word hysteria though the book is not always like this. In many instances the author could have used better words but didn't. For example "One moment the sky was empty the next it was there it didn't make a sound but they saw it." pg 82. This shows average vocabulary with no meaningful words. If you were the author what vocab would you use?