I would say in your case its caused by the heavy pruning. Any kind of stress seem to make them curl. I bet they will uncurl and look fine in a couple weeks.
I've been under aphid attack, temp ranges from 65 degrees to 95 back down to 65 and constant rain. Some that were curled bad look fine now. 1 will be curled the plant next to it is great looking.

I never really prune mine, this year I did do to the aphid attack. I only pruned the bottom branches that were curled and leathery looking.

Don't get me started on this Master Gardener thing that's sweeping the country. I swear you have to have certification for everything nowadays.

You can imagine the looks on all those Master Gardener faces when this little old uncertified girl shows up with the most beautiful transplants and then grows huge tomatoes on them.

I understand the program but it would be nice if they didn't lord over everyone like we have no knowledge whatever. Especially since our agricultural people haven't done such a good job of protecting the US soils.

Getting off my soapbox now.

"Master Gardener" or not, I've always thought it was a bad idea to prune determinate tomatoes. It's been my understanding that since the leaves of the plant are responsible for creating the sugars in the fruit and since determinate tomatoes ripen up all of their fruit at roughly the same time - the more leaves you have, the better tasting your fruit should be (assuming all else is right with your plants).

In general - and you'll hear many different views on these forums - pruning is only done to prevent issues with disease, have more manageable plants, or to have fewer but larger tomatoes. If you're plants are not unmanageable (not growing out of control, lying on ground, etc.) and if you don't currently see any issues with disease (blight, etc.), I would leave them alone.

I currently have two Rutger determinates in my garden and they are the bushiest, fullest plants in my garden. I've left them unpruned and they are by far the happiest. When they were very small I did prune the branches on the first 8" of the trunk so they wouldn't lay on the ground, but that was it. They currently have no issues with disease, are loaded with fruit, and are a general picture of health (in spite of non-stop rain and cool temps).

On the topic of "masters" of any kind, a man much wiser than me once told me, "There is no such thing as a master, everyone could stand to learn something new." I take that statement to heart and that's part of the reason I keep coming back to these forums :)

So pruning (an adult) determinate is always out, even if it's just taking leaves and not fruiting branches?

Really I can only blame myself for not standing by my own hunches; the person in question is a little pushy, but she had no way to "force" us to do what she told us.

I downloaded a book on how to prune tomatoes two weeks ago.I was hesitant to do it at first because we usually equate healthy plants with large amounts of foliage and branches. The author said he was raising tomatoes not leaves. So, I took the branches off the bottom of both types of plants. The indeterminates I pruned severely. Daily I take branches off and see no negative effect from doing so. I have lots of flowers and fruit coming on. The branches removed seem to be healing properly. It helps to reduce staking because of the elimination of so much weight as well as the amount of space they occupy. Some of them are main stems with just a few leaves on them. They don't look totally right because I'm not accustomed to seeing a skeletonized tomatoe plant. So far no problems.

mudmanfinisher: There is a big difference between pruning indeterminates (blah blah debate debate) and pruning determinates. Even most pro-pruning articles I have read make it clear that it should only be applied to indeterminates. At most, I've seen it suggested to prune below the first truss on bush varieties, but not above that.

I still think it is funny how it seems EVERYONE has strong opinions about pruning, might as well be the reformation/counter-reformation of the gardening world :)