I think we can toss Abel and Elijah in the mix here too.
Abel and Enoch were pre-Mosaic Law, so "for where no law is, there is no transgression." (Rom 4:15)
Elijah...Didn't die, but was taken away ala Enoch.
And as you pointed out, John had the Spirit of God from the womb.
I don't think any of the four committed sin.
Paul's Romans 3 writings of "all have committed sin" and "no not one" were quotes of OT writers designed to show the Jews of his day that they too needed the Savior.
Most of the quotes were from Rom. 3 are David's description of those who persecuted him in his flight from Saul, and, arguably, not intended for any one else, past or future. IMHO
Generally speaking, all men sin until they are converted, but God can still do as He pleases to get things done to satisfy prophesy or some other preordained future.