First, I hate red light cameras.
They are simply another way for Big Brother to interfere plus it is purely a revenue generator for cities that try to beef up their budgets and not employ real live officers.
Second, any EVOC or CEVO course will teach you that you were in the wrong. Unless the light was malfuntioning, I highly doubt it changed that quick.
What most likely occurred is this:
As you are driving, you become complacent, especially if roads are fairly empty, you have the radio on, maybe a phone, or even talking to a partner or dispatch. Whatever it is, something was distracting you from doing what you were supposed to be doing and that is driving.
The light you encountered is what is referred to as a "Stay Green" light. This means for the entire time you were approaching the light, you could see it was green. However on a conscious or subconscious level, you start to hedge your bets. You gamble it will stay green instead of being proactive and say to yourself, wow that light has been green for a couple hundred yards, I should start to let off gas and cover the brake, maybe even start applying if it changes to yellow.
Instead, you decided to continue on at regular speed which led to the inability to stop for passenger safety reasons OR you simply were not paying attention and when you did notice, same scenario was unavoidable.
Take it one step further since this was a "routine interfacility"...was everyone properly secured? If so, then stopping would of been the better choice as opposed to tboning or getting tboned and possibly flipping the unit and killing everyone.
However you did not seem concerned about this part which indicates traffic was not an issue. I could be wrong but just assuming from what you wrote. If traffic was not an issue, then I again assume inattention was the contributing factor to this "near miss" incident.
I know this was not the answer you were looking for but you fail to see the real issues and are instead focused on a ticket instead of actions that would have negated all of this in the first place.
It is also a great teaching story, so thank you.
Good Luck!