I no that a lack of copper could cause this problem
You can for sure save this one. Here is what to do...
First, cut off all the bad foliage. Anything that isn't green and healthy lookin, get rid of it. It there are bad leafs still hangin on, the plant just tries to fix the problem instead of growing.
Next, flush the plant. you want to make sure that if it was a nute burn that caused this, it is nuetralized by flushing.
Next, adjust your lighting. If you are running Flours or CFL's, adjust them about 6-8 inches from the tops. If you are running HIDs, go a little higher like 12-16 inches.
Ok, now for the next week or two, water every other day to every 3 days. I like to do one then the other.
Since the plant is stunted, you are trying to bring it out of shock, so don't give it any nutes, just a little water and plent of light. Make sure you have some air flow as well, you need to brake up the stale air if you don't have a fan on it.
And thats it. You should have that back to shape in no time. Good luck.