This could possibly be related to the team switch bug, but I found that some users are getting stuck listed as spectator even when they aren't spectating. How this is happening and how to reproduce it is anyones guess, but I did find that it occurs mainly when the client has to repeatedly choose their team at the beginning of a new round. IE: You click to pick red team, and instead of going to red team, you get the menu to choose teams again. This will happen several times, and sometimes it will cause the client to get stuck in limbo (not spectating, not on a team) forcing them to reconnect.

