>It depends too on exactly what he's testing for. If he really does just want to test for existence, then "AND NOT ISNULL(SomeObject)" might be an issue. An object can be null and still be an object. No?

Of course!
Exactly it is : "an unknown object reference"

Various cases

CLEAR

someObject = _screen
* someObject is a Known object reference, the object referenced is the SCREEN FORM
? m.someObject,    VARTYPE(m.someObject),  VARTYPE(m.someObject,.T.), TYPE("m.someObject")
*  Object                O                         O                         O

* someObject = CAST(NULL AS Object) VFP don't support this ( a design bug )

someObject = NULL
* someObject is a unKnown object reference
? m.someObject,    VARTYPE(m.someObject),  VARTYPE(m.someObject,.T.), TYPE("m.someObject")
*  Object                X                         O                         O

* another bug is
someObject = CREATEOBJECT("cx")

	someObject.RemoveObject("anotherObject")
	
	zombieObject = someObject.anotherObject
	* zombieObject is an object reference
	
	? m.zombieObject ,    VARTYPE(m.zombieObject ),  VARTYPE(m.zombieObject ,.T.), TYPE("m.zombieObject ")
	*  Object                O                         O                         O

	* It is a Class member
	on error ? message()
	
	REMOVEPROPERTY(someObject,"anotherObject")
	
	ON ERROR 
	
	* But the Class have 0 members !
	? "members count is", someObject.Objects.Count





DEFINE CLASS cx AS Custom

	ADD OBJECT anotherObject as Custom
	
ENDDEFINE