I mean, I’m sure Luke loves all of his students, and in his vision he sees them all dying, so him turning on his saber is him acting instinctually to protect them.
So Luke loves all his students except Ben? Why wouldn’t he talk with Ben, try to reason it out? Instead he instinctually pulls out his lightsaber, as if Ben isn’t Luke’s nephew and close friend. But we’re getting off topic here. I don’t think it’s possible to cut Luke trying to kill Ben without creating even more problems.