Life Span of Objects Managed by Master Data

I observed the following behavior on my NSManagedObject instances.

• ObjA is an instance of NSManagedObject downloaded from NSManagedObjectContext ContextA.
• I keep ObjA
• I get access to PropertyA ObjA (ObjA has no relationship, only basic properties) - everything works fine at this stage
• I remove ObjA from ContextA
• I keep ContextA
• ObjA is not freed (due to the extra save that I performed on it). I can still check it, for example, as saveCount.
• Access PropertyA ObjA -> I get SIGABRT

I am wondering if CoreData was designed to work or a side effect of my code.