He is wrong to object that you can't hold two different thoughts at the same time and that hence you can't remember God and attend to worldly details simultaneously. You can. God is not a thought, but an awareness on a higher level. Mind does not hold God. Certainly, mind can't have two objects of thought, for they are in duality, but they can be held by God's presence. Only here is the union of subject and object possible. All other thoughts are in duality.
-- Notebooks Category 23: Advanced Contemplation > Chapter 6: Advanced Meditation > # 256
-- Perspectives > Chapter 23: Advanced Contemplation > # 33