In samadhi, when senses are still and the mind is not active, there is no question of error. But to achieve that state, mindfulness is necessary from the very beginning. Look at Sridhamma Krishna's teaching about the women carrying the water pots on their head. It's actually mindfulness, moment to moment to moment, careful mindfulness, and a habitual mindfulness.
Swami Sarvapriyananda teaches the Katha Upanishad, one of India's most revered texts which is also a part of the Vedas. It is a collection of philosophical poems representing a conversation between the sage Naciketas and Yama (god of death). They discuss the nature of Atman, Brahman and Moksha(liberation).