Tempering with a document?
This is got to be some sort of a joke. Why would anyone temper with a document (Nobody would risk getting a 5 year ban from a country they are trying to immigrate)? On the same token, anyone can temper with the passport, educational documents, medical exam test results (e.g. giving somebody else's urine sample) ...
So then, we should get a Public Notary to certify that it was indeed our urine sample?
People are still confusing "Certified True Copy of the Original" and "Certification of the Translated Document". They are both done by the Public Notary, BUT THEY ARE 2 SEPARATE PROCESSES. Capisci?
So, they do not go hand in hand, like some people think ....
The translator or the Public Notary can NEVER authenticate the content of the document. So, you can alter the document as much as you want. Pulic Notary stamp can NEVER mean that the document has never been tempered with. For example, People can get their transcript from the university, and change all their marks using photoshop. Then, they would take that "new fake original" to Notary. Then Notary makes a Photocopy of this "new fake original" and you got yourself a Certified Copy of the "New Fake Original" transcript. THEN, AS A SEPARATE PROCESS, the Translator translates this "new fake original" OR "Certified Copy of the New Fake Original" and Notary stamps the Translator's Affidavit...
So, guess what? Our document ended being what you described above, and our document is also tempered with. Thus, your argument is invalid and has quite significant logic flaws.