Not too long ago a flag in user accounts was added to help denote SO staff
The catch here is that it doesn't indicate who was previously staff. This problem was originally limited to tertiary employees like Pops or Oded (where they didn't have a huge impact on front-facing sites), or famous people, but Shog9 alone has thousands of posts which were made while he was a community manager. While it would be incorrect to say current community managers cannot supersede what he said, there were a lot of times where I'm willing to bet they would simply let the policies he set forth ride (case in point). The problem is, there's no way to convince people now of anything any former employee said because there's no way to indicate they were staff when they said them.
This helps in future discussions, as people can trust that people aren't simply quoting random people and pretending they had any say in how SO ran.