Share with the class?
Do you seriously think that the gun vendor won’t be sued by someone? It makes no difference if he followed the rules or not, someone will try to sue him. If it isn’t the family members of one of the deceased, it will be some liberal third party busybody. They may or may not prevail in a lawsuit but you can bet your bottom dollar SOMEONE is going to sue the vendor over this. Not saying it is right, mind you, but it WILL happen.
See also Lipari vs. Sears amongst others.