Well good for you, I hope you never need to either. I haven't any reservations in entertaining the thought that a 9mm carbine would still be superior in target transition in low light and a confined space after firing on the first target, with my ears being no worse the wear and hopefully better than if I fired an AR.
That's all fine and dandy. Except for the "no worse the wear" part. It's still an unmuffled gunshot right by your head in a small enclosed space with no hearing protection.
Really, the issue was claiming eardrum rupture if you went with an intermediate rifle cartridge instead.