Although perhaps not a bug as such I am raising this in case it is an indication of an underlying problem. If you try to call a non-existent method on different controls you get different bahaviour. Usually it is ignored but a TextBox gives an error. I haven't tested all the controls.
B4X:
Sub App_Start
Form1.Show
Label1.NoSuchOp ' is ignored
Button1.NoSuchOp ' is ignored
TextBox1.NoSuchOp ' gives "object reference not set to an instance of an object"
End Sub