Of course, the DA can't let up. I'm sure he realizes this is stupid, but there's no way he can 'let a bomber go free'.
Furthermore, what does it matter if it's in a "secure" environment. Does CO2 sublimate faster on one site of a security checkpoint? Does a PET bottle become a lethal weapon when X-rayed in your luggage?
It was a stupid prank. The guy should be fired. 6 years in prison is a ridiculous prospect.
6 years in prison is quite excessive, but the punishment should certainly be more than "Oh you're fired." This person intentionally caused a major public disturbance, and should be fined accordingly. Maybe probation.
There's "putting a flaming bag of poop on your neighbor's doorstep" and then there's "delaying flights out of LAX".
If the intention is to play a prank at an airport instead of your own backyard, I think calling it a bomb is still legitimate because your motive is to make something (be it noise, or kill people). And consider the difference between an air port and your own backyard. The airport is a public property and is subject to 24/7 legal enforcement. Your backyard is not. You don't have 5000 people, 100 airplanes, people from 100 countries coming and leaving your backyard. Do you? And carrying that dry ice and place it at an airport, you have planned things. How do you know that dry ice was not part of an actual bomb scheme? What if it was used to distract the security? How do you know for sure it isn't?
Carrying a cellphone and intentionally set it on fire at an airport is a bomb. Carrying a cellphone and use it to call your mother but then the cell explode due to hardware failure is not a bomb, it's called an accident.
Accident vs intentional is a big difference. This is why your client is subject to criminal charges.
He could be a loner hating the government starting yesterday. People change their beliefs every day. How do you know he wasn't one of those people just happened to hate government a few days ago and thought it would be cool to "prank" an airport?
Probably.