Well, you already mentioned why and how it happened(Grin!!/wink wink).

When you harvest garlics and onions, either spread them on somethin like pine straw hay OR bunch them up from their stems an hang them until fully dry. Then you process and store them as normal.
Wet environmet is an invitation for a lot of microbio activities/diseases, like rotting/composting!!!

I harvested mine in July and I just think you waited way too long to pull them. When the tops start to turn brown and it hasn't rained for awhile, and I have also stopped watering the patch, that is the best time to harvest in July. But always in July, not later. And you, being further south, should harvest a little earlier than me. I pull the bulbs, brush them off and trim the roots down a little, then tie the tops with twine in groups of 12. I hang those bunches from my basement ceiling, and I have a dehumidifer running down there all the time. They get nice and dry like that and then they can be cut from the stems and stored in a box or basket which I also hang from the celing to give lots of ventilation. I never lose a head of garlic. Try to harvest yours in late June next year.

I guess I wasn't clear. I did harvest in June, but I didn't get around to trimming the tops and the roots until now. When I harvested, about 3/4 of the leaf tips had turned yellow.

I think my biggest mistake was keeping them at too high a temperature for 6 weeks. But I'm not sure if that's true or not.

I dont think keeping them at high temperatures is what caused your worm problem, even if it did cause your rot. I have had the worm problem for the first time this year but I have been reading and I think their called onion maggots. Try planting your garlic somewhere else this year and keep them in a cool and dry place until they have dried.