OOC: Here is my explanation:
*How the footage wasn't effected by the EMP: It was being fed into a separate device in a secure location, the feed was interrupted and broken by the EMP
*How Viktor knew it was an EMP: Nothing shorts out High-Grade Infinitus Cameras like an EMP. Bullets would not be able to break their casing easily and ripping them apart would make then cause an alarm. Infinitus likes to try and EMP proof their High-Grade equipment but their mechanics are not the best meaning only 1/10 are partially EMP proof, and considering the fact I must've glanced over the fact that you used an EMP and I messed up, it all makes sense in my mind

IC: "Put the place in lockdown, I'll go through the fire exit and get to the footage... you've been a very useful puppet Albert."