Because one picture tells a thousand words and there are lot of frames in this webm. http://webmup.com/PMjTu/vid.webm This bug doesn't occur after every game and I think it never happens when you select some old replay and watch it.
I've seen a similar issue when playing team armies without sharing. If you go into spectator mode before the end of the game it bugs out and won't let you toggle the enemy view in ChronoCam.
