All commands in MATLAB are actually implemented as functions. There is a command/function duality in existence. So you can always call the function as if you were issuing a command, if you provide the proper arguments to that function. This is true for any command, as far as I can think of.
But DBSTOP is surely one of those commands that were probably never expected to be used programmatically. Why would you be calling for a debug stop inside another function? Surely that would at least seem dangerous. So it looks like dbstop was written as if it would always be called in command form, even though in reality, the code lives inside the dbstop function itself. And it was documented as if that is the case.
