Primrose suddenly part of the Medic squad even though she was still not a trained Medic yet to be out in the field. It was pretty convenient for killing the lovable character though in the contrived explosion.
"Oh my I am just going to have a bunch of my friends die because I am too busy staring at the Mary Sue monsters trying to kill us instead of escaping up the sewer ladder!"
"A hurr durr I am going to believe what my mortal enemy President Snow is saying completely!"
and uuugh the ending, Katniss actually believes President Snow even though he is a notorious lier and bad guy and shoots Alma Coin killing the president of district 13 in front of THE ENTIRE CROWD OF PEOPLE. Also "HURRR I now live with Peeta who I only fell in love with because of the Hunger Games, and made babies! Now the kids play on the hill that is actually a mass grave!

"