Here's what I'm thinking happened, let me know if I'm way off base. I did overwater the tree, this I know. It got stressed out and shed leaves, but once the water level evened out and the seasonal citrus fertilizer spike (one of these things:
http://www.miraclegro.com/smg/goprod...ikes/prod70144) I added to the pot started leeching into the potting mix, the tree recovered and started putting off new growth.