I recently posted about how the leaves were dropping off of my potted Hamlin orange tree. The tree is about 5 feet high and I have had it a little over a year. Up to this point it was very healthy.
The leaf drop began very suddenly. Almost all the leaves are gone now and all the fruit also dropped off. It was carrying 21 half-grown oranges and a lot of blossoms. The weather was wildly swinging back and forth from near freezing to 80 degrees over the two weeks before the leaf drop. It was windy too.

I figured the drop was either caused by the temp swings or by too much water. One person here said it likely had root rot.

I've been leaving it alone and not watering it. Yesterday I took it out of its pot and planted it in the ground hoping that might help it out and also because I wanted to see the condition of the roots. I guess it's risky to add transplant shock to the equation but I don't think I have much to lose at this point.
The roots are not rotted at all. Also, they took up the entire pot but they were not circling the pot. They ran straight vertically. The soil was moist but not wet. It was probably fairly wet before I stopped watering it.
I planted the tree in a place where it will get good sun part of the day but also shade. The soil is the typical sandy Florida stuff that citrus likes. It is rather dry so it will probably suck any excess moisture out of the root ball.

Anyway I just wanted some feedback. What do you think caused the leaf drop, now that root rot is ruled out? I have other citrus but they are fine. What are the chances the tree will come back?

Thanks,
Ann