[Lazarus] An expression is returning false, why?

[Lubos Pintes]

Hello,
Sorry for possibly stupid subject and maybe off-topic question. In my 
UIA code, I am testing if a control has focus. So I have a FControl: 
TControl declared in my class.
Now say FControl contains a TForm1 instance, simply we have very simple 
program with just an empty window. Then an expression:
Result := FControl is TWinControl and TWinControl(FControl).Focused;
returns false. I am sure the form has focus..., because 
ShowMessage(BoolToStr(Focused)) returns -1, which represents true...