I was pretty surprised too. I completely gave up on knifing someone, even if they're not looking. One tiny little step away and the knife will miss.
I remember I was playing in Yemen, and I was in a building looking outside for the enemy UAV so I could shoot it down with my launcher. I hear not one, but two knifing noises coming from behind me. I didn't have my launcher out just yet, so I quickly turn around and I see an enemy with a gun who failed to knife me because I just barely stepped away. Keep in mind I had no idea he was behind me. So I shoot and kill him because he's still finishing the knifing animation. I actually felt kinda sorry for the guy. Next time, he'll know better than to knife someone instead of using a gun.
Wait I got it! Super Mario 3D Land will be in California and Super Mario 3D World will be in Florida. Zing! ~AloofGuyXXVII