My first though is that it can be be beneficial to have guns in different places.
This is one of those cases where the assailant got the drop on the victims. In this situation, if you have a gun on your night stand - it might not be the best decision to try to grab it. Because the assailant actually has already told you that you're at least going to live long enough to dress and drive to an ATM.
Having an accesable gun in your closet seems to be a great option.
The story isn't clear where the homeowner retreived his gun from but anyway those were my thoughts.