One of Widowmaker's screens was trained on Shimada just to make sure she could keep tabs on the ninja in case he decided to stop fighting War's influence. She was positive she could shoot him before he did any serious damage to Reaper, but he was very fast. She wouldn't be able to stop him before he engaged.

It better not come to that.

"Guns and Roses, do secure Tal before War's ability rekindles his desire to fight."

Otherwise, Widowmaker was more interested in keeping tabs on the other fights and seeing who these hostages were.