When a component instance was removed from the DOM, and it happened to have been recently in focus, there were several constructs in Flex that were pinning the instance in memory, preventing the player from GC'ing it. Namely, the HaloFocusRect and the focusableCandidates array within the FocusManager.
Reviewer: Alex, Darrell
Doc Notes: None
Bug Notes: Related to SDK-14781 and the three duplicates (SDK-18717, SDK-18755, SDK-18575), note this is not a comlete fix as there is one outstanding player issue logged (2267790).