The argument is this: if a case that is otherwise probation required under 42.12 section 15 but the defense has the jury set punishment, then under 42.12 section 4(d)(2)the jury can only impose jail? Is this a correct reading of the law?

No, for a SJF, if the D elects jury punishment, then the jury sets the confinement and punishment. The judge must automatically follow 42.12, sec. 15, as to probation. See art. 42.12, sec. 4(d)(2). That subsection is merely saying that the D is not eligible for probation "under this section." The D is still eligible under another section, namely, sec. 15, which makes probation the job of the judge.

Ha, yes thank you. That should clear up our way to early debate.