Last fall, the garlic I planted in late October came up early. While the fall weather had been a bit warmer than usual, that had been the trend for the past few years. I purchased a multitude of garlic around our yard, as I hear it's a rabbit deterrent. The instructions advised an October planting for my zone. I planted around the end of October. A couple of weeks later, mid-November, I noticed a few garlic shoots emerging from each of my garlic hotspots. Consulting the google machine, asking if that garlic was ruined for the next summer, I received differing answers and hence, no conclusion.
I have my answer. As with any non-scientific exploration, YMMV. As the pictures indicate, no spring garlic. The two garlic beds with the greatest fall garlic emergence did not produce any garlic shoots for spring. It's possible, in fact likely, that garlic that has smaller shoots that do not fully emerge will have enough stored plant energy to re-emerge in the spring. In any case, I will plant my garlic later in the fall from now on. At least wait until November.