Nah, they wouldn't have rethought it.
It would actually convince them that they made the right decision since it shows that if all those people killed by mass shooters had guns on them at the time it happened they might still be alive.
USA haters gonna hate though so no surprise.
Thank the Lord for our 2nd amendment rights.
It makes what is going on in Australia right now with their tyrannical police state far less likely to happen here.