The best way I found to counter this is with a simple counter-example. This argument is implying that all false beliefs are formed causally, based on reason. This however is what some call a Possibility Fallacy, that is assuming that having no explanation is equivalent to not being able to have one. Simply because it just so happens that all false beliefs are formed causally, it does not follow that all causally formed beliefs are false. it's like saying "lunch meat is often baloney, therefore all lunch meat is baloney."