Grimlock ♥ Ultra Magnus

"Objects pelt me, extra security hold the crowd back as they pulsate at me..."

Pulsate at feels like an odd choice.   Around would feel less odd.   But really, something that described more of the riot going on would be way more appropriate. 

"I arrive back at the holding cell, covered in whatever filth people have spat and thrown at me..."

Why would you not use thrown first.   'Whatever filth people have thrown at me,' makes sense.   People were throwing filth and will wash their hands later.   'Whatever filth people have thrown and spat at me,' still has spat go back to filth.   But especially with spat first it implies they have filth in their mouth that they have spat at her.   I have to admit to laughing out loud at this. 

"I arrive back at the holding cell, covered in whatever filth people have thrown at me," actually does just fine.   If you have to mention spitting I would do so separately.   Because otherwise what are they putting in their mouth?  Garbage?   Worse?   Y'know what, never mind, I don't wanna know...