Does Paul say the law is like old Adam and just generates sin?
Paul explicitly answers no. The law is not equivalent to old Adam, nor does it merely produce sin. Old Adam generated sins that ended in death, but the law is not the source of sin in that way; the contrast is clear.
Les teaches that in this passage Paul asks whether the law is like old Adam, whether the law is something that just generates sin, and the answer is no. The earlier context describes being in the flesh under old Adam, where the motions of sins which were by the law worked in the members to bring forth fruit unto death, and the wages old Adam pays is eternal death. But the flip side is that believers are delivered from the law, being dead wherein they were held under old Adam and the curse, to serve in newness of spirit under the Holy Spirit, the Word of God, and the Creator God, not in the oldness of the letter. So the law is not the generator of sin as old Adam is.
What shall we say then? Is the law sin? God forbid. Nay, I had not known sin, but by the law: for I had not known lust, except the law had said, Thou shalt not covet.
More Questions
How does the Law make us aware of our sin?
Paul would not have known about his old sin nature except through the Law, and he would not have known what lust was except that the Law said, Thou shalt not.