Regardless of caliber, rounds that have contacted the suspect, and rounds missed, if he is still moving and able to shoot back why not continue to shoot? At that point in time does anyone seriously care what round they are using? Sure, I think the hit percentage should be higher, but their job isn't SOLELY to shoot bad guys.
"Today is victory over yourself of yesterday; tomorrow is your victory over lesser men." - Miyamoto Musashi
[Insert random irrelevant religious quote here]