A good reason for the concealed hammer that I don't believe has been
mentioned: Suppose you are holding the bad guy at gunpoint waiting
for the cavalry to arrive. If you have a hammer you might cock it without
thinking much about it. The SA would have a lighter trigger than the DAO
which you could not cock. In a high stress moment like this you could
accidentally shoot the bad guy.
Not a high possibility? Not much more so than snagging on the draw.
I have had several students relate several examples of holding burglars
at gunpoint. Have never had one report a discharge or other problem
from snagging on the draw.

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