So your implementing a spectator mode with a 3 minute delay...why bother, it's pointless.
Take a page from HoN, allow live spectator mode with no delay seeing what the player you spectate is able to see. Also, the player you are trying to watch has to authorize you to watch them, eliminating the risk of a friend of someone playing on one team watching the other team's movements. Because again, you can only see what the player you are watching sees. Why can't you make your spectator mode like this?
This new mode is really no different then watching a game on youtube. Who wants to watch a game with a 3 minute delay that is over while your still watching it.
Time to get with updated technology