Wow, I always find it utterly amazing how two intelligent people can miscommunicate so badly!
Schneibster, Sphenisc didn't didn't agree with the OP in any way shape or form. He simply pointed out, in far too many words, that the regression isn't linear, so the OP is BS. And your estimate is incorrect, because it uses a linear regression, which doesn't apply, although the true model would probably be pretty involved and ugly. And no, I'm not even going to attempt to provide it.
Sphenisc, it was bloody clear that Scheibster didn't get what you were saying, so why didn't you just tell him that he'd misunderstood and that you weren't actually disagreeing with him or supporting the OP, just adding a codicil that, not only was the OP writer's maths wrong, but the regression can't be treated that way anyway.
And the pair of you, stop being such confrontational asshats!