I don't think the reasoning is incorrect. It went like this: 1. What if the motion of light is influenced by gravity, as suggested by Newton's theory of corpus

I don't think the reasoning is incorrect. It went like this: 1. What if the motion of light is influenced by gravity, as suggested by Newton's theory of corpuscles? (It is, just not in the way he thought.) 2. And what if there are supermassive, super-dense objects? (Turns out there are.) 3. Then light would be unable to escape such objects. That's pretty remarkable in my opinion, and no more "wrong" in its way than Newton's theory of gravity which was also correct for the wrong reasons.