By the time Mike yelled for Yang Yi to back up, Yang Yi had actually already started moving forward, his actions quicker than Mike's shouts.
Just then, over the phone, Brian bellowed, "Charles has been shot!"
Being suddenly ambushed is one of the most dangerous unforeseen events one can encounter, bar none.
Those with a plan always have a significant advantage; no matter how vigilant the unsuspecting party is, it's impossible to constantly prevent the enemy from finding an opportunity, and being shot at point-blank range while in a moving vehicle leaves no room for any skills to be utilized.
It's no exaggeration to say that Yang Yi's detection of the irregularity and subsequent warning saved the lives of Brian and the others. Although Charles had been shot, it was only Charles who was injured. Had it not been for Yang Yi's early detection of the anomaly, alerting Brian and the others, that round of gunfire could have claimed all three of their lives.
