Update on Olea's, or, it is not as easy as expected

Three days ago I looked in Olea's window and was surprised by what I saw.

Only some days earlier, all those combs were covered with bees.  (These are the last combs in the box.  There are still a dozen combs full of bees.)  Where had they gone?  I looked on the ground in front of the hive and was relieved not to see hundreds of corpses.  Have you figured it out yet?
Of course I cannot be certain, but I think they swarmed.  I looked all around our yard and into the neighbors' yard looking for a bunch of bees flying around a cluster.  No luck. 
Today I took the MAQ out of Olea's.  When I put it in, I put 2 empty bars above it.  In the 8 days since, the bees had built a large comb on one bar and a nubbin on the other.  The larger was mostly drone cell size and there was a patch of nectar, too.  I placed the bars on the hive while I retrieved the MAQ and moved the other bars back together.  I decided to place the 2 bars into the hive even though there already was so much empty comb.
Moving things shook the box a bit and the large comb fell over onto the ground.

One of the things that can make bees testy is being queenless.  After a colony swarms, there will not be a laying queen for up to 2 weeks.  Throughout my working on the hive I was besieged by angry soldier bees, adding a bit of credence to my theory of what happened to the missing bees.  It got so annoying that I fetched by honey-b-healthy sprayer and repeatedly spritzed the bees flying about my face.
I did get the hive back together with the new combs towards the back.  There are now 20 bars in Oleas.  I will look into Olea's around the 24th to look for evidence of a laying queen.