I work odd shifts and at my workplace there are no 'zone friendly' foods available if I happen to forget to pack enough food. Today I was a block short and I'm freaking out because I ate half a protein bar to try to make up the shortage. It was a Pria carb select bar-10g P,8g F,21g C(17g sugar alcohol)-YIKES!!! Would I be better off to skip that block(a carb)completely or eat a block of carbs when I get home? I try to keep canned veggies and tuna/chicken in my locker just in case but didn't have any 'back ups' stored there today.
Also, I don't have any opportunities to leave the workplace to search for 'good' food.

Well, it is going to happen sooner or later. It has happened to me, I might forget part of my lunch, or I may forget to grab my lunch bag entirely!

I would not fret too much over it. If you were only missing one carb block, it might still be adequate to keep you in the Zone. I think, in your case, I would eat lunch just the way you had it, and if you were to run into trouble, then eat the Pria bar later (not exactly balanced, but since I don't know your other choices, it might be the lesser of the other evils out there).

Have you considered ordering some Zone bars online? Just a suggestion. I try to keep an emergency supply. I don't eat them on a regular basis, but if I am in a pinch, I will use them.