No! Ben Solo's mind was infected, twisted, and manipulated by Snoke, a proxy of Darth Sidious. He fell to the Dark Side sometime before Luke realized the extent of the danger. He reached into Ben's mind and found only darkness, along with a premonition of the destruction and death he would bring to the foundling Jedi Order. Instinctively, Luke activated his lightsaber, determined to extinguish the threat. However, he immediately came to his senses and would never have harmed the boy. Solo, however, awoke and saw Luke standing over him. He then attacked him, knocking him unconscious, and burned the rest of the Order to the ground. When Luke came to, he blamed himself - but the fault lies at Palpatine's feet.