Having a smoking lesion make you choose smoking is vague. Does it make you choose smoking by increasing the utility you gain from smoking, but not affecting your ability to reason based on this utility? Or does it make you choose smoking by affecting your ability to do logical reasoning?

In the former case, switching from nonsmoking to smoking because you made a logical conclusion should not affect your chances of dying, even though switching to smoking in general should affect your chance of dying.

In the latter case, switching to smoking should affect your chance of dying, but you are then asking a question which presupposes under some circumstances that you can't answer it.