If someone commits an act of major shirk can I see him to be a mushrik? Or until he’s told this is haram but isn’t convinced and still persists in the major shirk? The one who accuses an innocent of kufr the kufr falls back on him, yet the one who doesn’t consider a kafir a kafir is a kafir himself

Ustadh AbdulAziz al-Haqqan

Do not apply general rulings to individuals by name. There is a large difference between a scholar saying that an act is shirk or kufr, and a ruling being passed on a particular person that he is a mushrik or a kafir. Always take these matters to the scholars.