[accidental video]
[There's a loud smash and Sam's cell cuts on as it's flung from his pocket and lands on its side. It gives a full and extremely terrifying view of an epic robot droid death match in a forest.
There's at least two Decepticons that are visible to the camera, though they're rather lopsided because of the angle. Sam's voice can be heard shouting at the top of his lungs "Optimus!", and then we see a view of Sam's foot as he arranges himself, then the camera is clear again.
Just in time for a view of Megatron stabbing Prime through the chest then literally blowing Optimus' chassis out with his gun.
The last thing seen before the camera is cut when Sam snatches it up is Optimus' flickering optics, and the words;]
Run, Sam.