Polyp bail out...I have seen it a few times. I would say it is a form of self preservation and the result of unhappy conditions. Is it possible that your tank may have gotten too warm? Bad water quality is another possible culprit...corals require so little direct feeding, I wouldn't leave oyster feast in the hands of the untrained. Again, hard to say what upset them...but probably worth a good water test to see if anything is out of whack and a nice water and carbon change as a precaution regardless of the water test.

As for the loose duncans, I would leave them alone if they seem "happy" now. The chance long term that they will make it is low IME. But if conditions improve and stay consistent, they may attach and start to regrow.

More importantly, where are the vacation (fish) pics?