KeyExists method sometimes returns true even when document never exists on server

Seeing this issue randomly where in KeyExists() returns true to a key that doesn’t exist and never existed within any bucket.
Is this a bug or is there a fix for this issue or a possible reliable workaround ?

It sounds like an issue given that there aren’t any existing known issues. Can you file one on the NCBC project over at couchbase.com/issues? Please attach any sample code.