Answer: Indeed, we can prove this!

(Beraisa #1): The following apply to blood that must be put on the Yesod:

It must be washed, intent (Chutz) takes effect on it, and one is liable for it outside.

None of these apply to blood that is poured into the Amah.

Conclusion: The Beraisa must be R. Nechemyah, for he is Mechayev for Shirayim outside, and it says that Shirayim must be washed and intent takes effect on them.

Contradiction (Beraisa #2): The law of Shirayim and Eimurim is different (than blood that is Mechaper). Since they are not Me'akev Kaparah, intent does not take effect on them.

Answer (and rejection of Answer (a)): Beraisa #1 refers to blood of the last three Matanos of a Chatas. (Therefore, we have no source that R. Nechemyah obligates washing Shirayim.)

Objection: The last three Matanos are put on the Keranos. The Beraisa (#1) says that they are put on the Yesod!

Answer: It means that what remains of them is put on the Yesod.

Question (against Rav Papa): The Beraisa says that intent takes effect on it. [Rav Papa] said that what does not permit anything, intent in it is not Mefagel, and it does not (disqualify the Korban if it) enters the Heichal, like Shirayim!

Answer: The Beraisa discusses blood of inner Chata'os.

Inference: One is exempt for offering the last three Matanos of outer Chata'os outside the Mikdash, and it need not be washed.

Question: If so, why did the Beraisa distinguish between (blood put on) the Yesod and (blood poured into) the Amah? It should have distinguished between inner and outer Chata'os!

Answer: The Beraisa is R. Nechemyah. He is Mechayav for Shirayim (even of outer Chata'os) outside;

He distinguished between the Yesod and the Amah, for these differ in all three respects (washing, intent and outside). He could not teach that Shirayim of inner and outer Chata'os differ in all three respects (since one is liable for both of them outside).

Answer #2 (to Question 2:d (38b) - Ravina): The Mishnah said 'if blood splashed from the Keren or the Yesod...' This refers to blood that splashed off the Keren, or blood Ra'uy for the Yesod.

Question (Rav Tachlifa bar Gaza): You should (be consistent and) say that it refers to blood Ra'uy for the Keren or for the Yesod!

Answer (Ravina): The Mishnah would not need to teach both of them. If blood Ra'uy for the Keren need not be washed, all the more so blood Ra'uy for the Yesod need not!

(Beraisa): "V'Asah (he will offer Par He'elem Davar) Ka'asher Asah (like the Chatas of a Kohen Mashu'ach)" is a second command to perform all the Matanos, therefore, all are Me'akev. If one was omitted, the Par did not atone at all.

Suggestion: Perhaps this applies only to the seven Haza'os (on the Paroches), for seven Haza'os are always Me'akev. What is the source that the four Matanos (on the Keranos of the inner Mizbe'ach) are Me'akev?

Answer: "Ken Ya'aseh." (The Beraisa proceeds to expound the entire verse.)

"La'Par" refers to the Par of Yom Kipur (that atones for the Kohanim.) "Ka'Asher Asah la'Par" refers to the Par Chatas of a Mashu'ach (for transgressing through his own mistaken Hora'ah). "Ha'Chatas" refers to Se'ir Avodah Zarah (brought if most of Yisrael transgressed idolatry due to a mistaken Hora'ah of the Great Sanhedrin.)

Suggestion: The Musaf of festivals and Rosh Chodesh includes a Sa'ir Chatas. Perhaps also it is included (in this verse, and it is offered like an inner Chatas)!

Rejection: (He will do) "Lo" (to it, Se'ir Avodah Zarah, but not to other Se'irim).

Question: ("Ha'Chatas" and "Lo" do not connote one Sa'ir more than the other.) Why do we include Se'ir Avodah Zarah and exclude Se'irim of the festivals?

Answer: It is more reasonable to include the former, for they atone for a known Aveirah (like Par He'elem Davar), whereas Se'irim of the festivals atone for Aveiros (of Tum'ah) that no one ever knew about.

"V'Chiper" - even if the Zekenim did not do Semichah on it;

"V'Nislach" - even if the Shirayim were not put on the Yesod.

Question: (The verse did not specify which Avodos are Me'akev and which are not). Why do we say that Matanos are Me'akev, and Semichah and Shirayim are not?

Answer: Wherever the Torah requires Haza'ah it is Me'akev. Semichah and Shirayim are (usually) not Me'akev.