Occam,
You say :
As for brood/eggs, the frames were looking really good actually, there were 3 frames of mostly capped brood, 4 of mixed eggs, larva, and capped, and a couple of resources. No fault in her laying, which is what's making me question the swarming. With the different stages the hive would have had to have swarmed earlier than I was thinking I'm pretty sure
If this was right after you thought they swarmed, then they didn?t swarm. Usually the bees put the queen on a diet to drop her to flying weight and she slows down her laying. Once she leaves, in three days, there won?t bee any eggs at all.
How many days after they slowed down did you inspect this hive?
Jim Altmiller