On Tuesday, 3 days ago, I got stung and made some mistakes. I was preparing my hives for the winter and have small hive beetle in my last inspection.
My set up prior to Tuesday: I have two hives on a pallet about 18 inches apart. Each hive was one deep and three mediums.
On Tuesday: I went completely through one hive and put two beetle trap per box. Got stung at bottom box. I removed one medium and moved all full frames down and to the remain two full frames to place in second hive. On top of the last super box i placed my inner cover on top of that I placed a top feeder then my outer top cover.
On the second hive I placed the medium from the first hive one top and a bee escape below two mediums ( one from each hive)

Today I arrived to see alot of fighting at the top of my hives. The hive with the feeder had yellow jackets at the top trying to get in. I assume there was enough of a gap between the outer cover and the feeder to allow access. Inside the feeder the entire surface was covered with dead drowned bees. In the second hive the bees were escaping the top as soon as i opened it. There was a large amount of dead bees on the bee escape as well. I removed the feeder from the first hive and the extra partial full box ( one built out frame) from the second hive as well as the bee escape. The hive are now compressed down to just full boxes.

I am concerned the two hives are robbing each other. My plan is in the morning I am going to put on an entrance reducer, then in a few days re-add the feeders and place beetle traps in second hive.
Is there anything else I can do, and how bad as this mistake?
Thanks in advance.