One person says that arguing is a tool that can be used to save your own life - Not it is the tool to save your life in every case it requires it.
The other person completely disagrees and says that arguing will make things worse, and be the thing that actually causes your death. - Though not neccessarily by gunfire.
If we are taking the gunman out of blame's path, they are equally responsible for their deaths, which could (or could not) be through creating tedium or noise, or indeed through the second man conspiring with the gunman, as may be hinted in "arguing will make things worse, and be the thing that actually causes your death."
But to blindly speculate "ENOUGH!" may simply be referring to the number of bullets left in the gunman's weapon, he could just be going around shooting people in bars, and took an hour to wait for the heat to pass before he made his next killing of the day. 