When switching from the standard in-game chat (in the bot-right corner) to the forum tab there seeing the latest entry that was made to the forum is incorrect whenever a player edits the post after it already appeared in the forum tab.
You always see the original post there but never anything that was edited afterwards.
Example: You cannot see this example in the forum tab of the chat box because it was added by editing an existing post.
Screenshot to prove the example when it's not the latest post anymore:
http://prntscr.com/jwgjk4