- Carly lost her brother in the line of duty at some point before the film, and its clear she still misses him and doesnt want to lose Sam the same way.
- The death of Ironhide. He is betrayed and shot by Sentinel and slowly and painfully rusts away.
- As Sentinel is setting up the pillars, Optimus pleads with him to stop and begs Sentinel to tell him why. Optimus is clearly heartbroken (sparkbroken?) at his former mentors betrayal.
Sentinel Prime: Optimus, all I ever wanted was the survival of our race. You must see why I had to betray you.Optimus Prime: You didnt betray me. You betrayed yourself.
- At the end of the movie, Optimus is mournful that his hero chose to go against his teachings and that he has no choice but to kill Sentinel to save Earth. In turn Sentinel is mournful that his lifelong dream to save Cybertron has failed and pleads with Optimus to understand.
- The destruction of the Xantium. First Sam has to watch the Autobots, especially Bumblebee, leave Earth forever which causes him to visibly but silently cry as Optimus and Bumblebee say their goodbyes. Then he watches the spaceships destruction, causing him to believe they are dead. Worst of all, Sam knowingly but unwillingly played a part in their demise. Fortunately, the Autobots faked their exile and death.
- R.I.P. Que.
- If watching the Autobots seemingly die the first time wasnt enough, Sam watches Bumblebee nearly die again. This time there is no trickery. Sam desperately tries to save Bumblebee but realizes he cant do anything but watch as Bumblebee says his final goodbye.
Tearjerker / Transformers: Dark of the Moon