Respectfully, this feels like you trying to force a wise interpretation out of a weird thing he did once. Like, he cursed a tree and it died. People pointed it out, and he explained HOW he did it, as if that was the lesson to be learned. When asked WHY he did it, he refused to answer because of some metaphysical bullshit.
To me, "his disciples heard him say it" rings of "I'm not making this shit up. Ask Luke if you don't believe me."