Identify this tomato problem
 

My friend has soil grown tomatoes that has a problem. It's interesting b/c the plant is a Sungold and I have a clone from the same plant. My plant was removed from my hydroponic system recently b/c it never recovered from a droopy/wilty' leaf problem.

His Sungold plants leaves now looks like this:

http://i40.tinypic.com/2hhna7s.jpg

It's the only plant that seems affected. I told him I could post it to the forums to find out what is up. I recommended immediate removal but he doesn't want to b/c it as "healthy" looking fruit developing.

What do you think is going on?

Long story short, from what I have read it's a nutrient deficiency or toxicity. The only real way to be sure exactly is a analysis of the plant tissue by a lab.

looks like Septoria leaf spot, interestingly my sungolds are also suffering from this
Septoria leaf spot

I like this reply and it does look like the images in the link.

Septoria leaf spot from what I read is a Fungus diseases:

"Septoria leaf spot (Septoria blight):
Common in Atlantic, Central states, and Southern Plains states. Most severe in rainy seasons, crowded patches. Usually not seen before mid-July. Older leaves have many, small, watersoaked spots, usually 1-2mm diameter. Leaves may drop, and progressive defoliation may occur. Clean cultivation, clean up at the end of season, and staying out of wet tomato patches (you can spread the spores) help."

From:
Tomato Plant Problems FAQ by Kay Klier

There is also bacterial speck, which manifests early on in the cooler weather.