One desd bird doesn't mean it only killed one. Also, the other comments that it's feral cats is spot on.
One concern is well fed outdoor cats normalized people who have feral cats , especially the kinds they dump a bag of food every now and then and think they mean they aren't part of the problem.
And in general, people should not allow their pets outside. We do it for cats but not other animals because people think their cats is never a nuisance; bird killer or otherwise.
All the science says don't let your cat out. Pointing at one specific stat and ripping it apart and claiming victory is exactly how we allowed climate change to just slip away for over 60 years now.
It's not a problem if I dump some motor oil into the ground because oil tankers leaker more! Either too contribute or too don't and I'm going to be a dick to anyone that contributes no matter how little.