Hasn't the CFL done something like this for several years now? I seem to remember a video of the extra official (I forget his title) doing some things like telling the umpire he placed the ball on the wrong hash and things like that.
Also, what exactly will be w/in this guy's purview? Can he call anything he sees? Or will the on-field crew have to request assistance from him (kind of like an MLB umpire review)? Or what?
It'll be interesting to see how all this shakes out.
For the STAR official, this is what has been defined for responsibility:
ARTICLE 5. SENIOR TECHNOLOGY ADVISOR TO THE REFEREE (STAR). The STAR will be located in the Replay Booth with access to video technology and the ability to hear and communicate with game officials through the official-to-official communication system. The STAR is an officiating expert who has on-field experience as a game official. The STAR will advise the officiating crew of any relevant information on the following types of rulings: (a) Game Administration. (b) Possession. (c) Touching of a loose ball, boundary line, goal line, or end line. (d) The location of the football relative to the boundary line, line of scrimmage, line to gain, or goal line. (e) Down by contact (when the player is not ruled down by contact on the field). (f) Fouls for Facemask and Unnecessary Roughness Against a Defenseless Player (g) Number of players on the field at the snap. (h) Any other information requested by the Referee.