In the end how it works is already defined (See my previous post). Its up to GM to call it as they see it. Cannon has examples of it being done. If you as GM think its bad news, then its bad news. But i'd be sure you have good answer when player start asking questions.

See YS 288 Side Bar, "With Evocation's Methods and Speed".

I think it would come down to intent. Did you drop the spell intending to kill the guy? Did you drop the spell b/c you were unable to keep it going? Did you drop the spell thinking the man was going to be safe? Did you drop the spell b/c he was about shoot you while suspended in the Air? All of these questions represent different scenarios of what could be the same action. If the intent to kill was there, then I'd say First law maybe be a part of this, but if it was not intended as an attack then I'd say not. Remember that stress is not damage, only consequences are.

Sorry to sidetrack, but can a focused practitioner take refinement?

Yes they can see Channeling in YS 181. They are somewhat limited in what they can do with it.

Most of refinement refers to evocation and thaumaturgy, not channeling or ritual, so the specialization from refinement doesn't look like it fits. And the template for focused practitioner doesn't say you can take refinement, whereas the template for sorcerer or wizard does say (and in the case of sorcerer, how much).

They are limited in what they can gain from it b/c they they can't ever build a good pyramid for a major bonus. But They can take it for items slots as much as they like, So foci, Potions, and enchanted items are all open as far as they can go.

Sorcerers are the ones limited in the amount of refinement they can take See page YS 81. They can only take 1 time per spell ability. This is balanced by the fact they are encouraged to take law breaker. (Do the math and see which one is better. lol) But as a note I also would interpret that to mean they could still take refinement for the purposes of item slots.  (yeah know I'm Cheesy get over it.)

Is that gritty theme Word of Jim?

If you have read the books, and don't think its a gritty noir series, then I wonder if we are really reading the same books.

The question of the thread wasn't is the system balance concerning mortals. It was are mortals Viable. I agree that trying to have high level of realism in a game where Magic is a Central theme is a little too much to ask. But gritty is also a theme of the Dresden files, and is one that should be payed attention to. Every gaming group is different, and it is important to do what is right for the game your in. Mortals are viable. Are they as "powerful" as other concepts? No. Its very hard to compete with a power that is specifically tagged to make the Impossible, Possible.
But that does not mean that Mortals can't show up and rock faces. Mortal have basically no limiters, they are versatile, and there are a LOT of them. So its true that 1v1 most mortal aren't really a match (And there are plenty of exceptions). But lets face it resources and contacts are skills in this game, and so there is nothing wrong with using them. Can't kill the local black court yourself? How about calling Monoc and see if they are willing to take that contract? Or perhaps you know "Just the Guy", who can get you in contact with that break away group of ex-spetsnaz. A Million buck in brief case later you can get some serious stuff done. 

sure, if you spend the shifts to make it zone wide, why not let everyone's aspect be tagged.  This would include enemies tagging the aspects as well...

True if they were in that zone when the spell was cast of course.

As far as i can tell if your willing to AoE a spell that applying the aspect, each person who gets the effect should get a free tag of it. Think something along the lines of group telepathy, applying Perfect Team Work, or some kind of Reverse Entropic Effect, Amazing Luck.  In the end it will be GM call, i'm certain plenty of folks will look at this and go No wai!!! and say that you need to spend for any use beyond the first. But it is a good idea to motivate wizards to do something other then Swing as big a magic attack as possible, Giving your whole team a free tag is most like easily as effective, and way more group friendly.