Pesachim 16 – Torah or Rabbinic Impurity?

There is a long disputation, lasting several pages, about the ways that ritual impurity is or is not communicated through fluids. While generally true, there seems to have been an exception made for the blood and water of sacrifice in the Temple:

R. Eleazar said: Liquids have no uncleanness at all [by Scriptural law]; the proof is that Jose b. Jo'ezer of Zeredah testified . . . that the fluids (blood and water) in the [Temple] slaughter-house are clean.

Now if it were Torah law, no exception could have been made! So the impurity, such as it is, must be Rabbinic law.

Come and hear: If blood became unclean and he [the priest] sprinkled it unwittingly, it [the sacrifice] is accepted; if deliberately, it is not accepted?

Now this is interesting, because the Torah makes no accommodation for deliberate or unwitting in this case.

 It was Rabbinically [unclean], this not being in accordance with R. Jose b. Jo'ezer of Zeredah.

Or perhaps not – maybe there is a scriptural “out” – the Priest’s headplate, which was supposed to provide a certain kind of atonement on its own:

Come and hear: For what does the headplate propitiate? For the blood, flesh, and the fat which were defiled, whether in ignorance or deliberately, accidentally or intentionally. . .[It was defiled] by Rabbinical law [only], this not being in accordance with Jose b. Jo'ezer of Zeredah.

This statement of Jose b. Jo'ezer of Zeredah comes, by the way, as a testimony during a historic battle for control of the Sanhedrin between R. Gamaliel and R. Joshua. “Traditional” rabbinic laws were examined to determine their validity.