How are people shooting through level 3 knockdown shield with less than a clip?

Literally just finished a duos in season 6, got knocked and then one-tapped with a lvl2 knockdown deployed, at decent range(maybe 15m) by a volt, through the face of the shield...you cant tell me something isnt broken there. The other player was also lvl 9, definitely a smurf although ive been playing since season 2 and I cant even recall a time where there was a legitimate "Hacker" in the game. Im just confused as to how I got one-tapped by an smg from my perspective, through the face of the shield. Also im on PS, so hacking should be even more rare.