Stopping Play for Injury

[Rich]

Originally Posted by BillyMac

5-8-2-Note: When a player is injured, the official may suspend play after the ball is dead or is in control of the injured player’s team or when the opponents complete a play. A play is completed when a team loses control (including throwing for goal) or withholds the ball from play by ceasing to attempt to score or advance the ball to a scoring position. When necessary to protect an injured player, the official may immediately suspend play.

Note the word "may" which is quite different from shall.

And the last sentence pretty much gives the official free reign to do whatever he/she wants.