Answer: What's Wrong with this Plant? Hardening Off
I've only gotten a few guesses, but they are right. The answer to the tomato problem was that the plant was not "hardened off" or acclimated to the cold temperatures gradually. Most greenhouse plants need to be exposed to outdoor temperatures over a few days, before they are ready for chilly temperatures. Since we've had an unfavorable cold weather this spring, most tender veggies--such as tomatoes, peppers, melons, and squash have struggled. Their leaves will scorch and look washed out when they are pushed from a balmy greenhouse environment to outdoor temperatures in the 40's and 50's.
Here is more information on hardening off transplants from the greenhouse put out by the University of Maryland. This might come in handy when helping with diagnostic clinic at the Gardens and you can impress your families and friends.