Everything can be appealed to the US supreme court.This is going to open up the flood gates for the weapon makers to face justice for the death and suffering they've helped to inflict on our nation.
The state Supreme Court of Connecticut has ruled against the weapon makers and for the people of our nation.
This can't be taken to the Federal Supreme Court so it can't be overturned.
Aside form that...
This is no different than arguing Ford is legally liable for the deaths caused by someone stealing a Mustang , getting drunk and running a school bus full of kids over a cliff.