Legal Question in Product Liability in California

Plagerism is not a legal term and has no direct legal consequences, although it may concurrently breach some legal obligation or violate some law depending on the details. Plagerism is simply using the written work of someone else and passing it off as your own. If I'm writing a story and I use parts of another story by another author without identifying the source, and then give it to a friend and say "check out this great story I wrote." That is plagerism, but I can't think of anything illegal about it. On the other hand, you could make exact counterfeit copies of a DVD movie, with all the credits intact, and then sell them on the black market, and you would be completely innocent of plagerism, but would be committing a serious crime.

So, to answer your exact question, it would be plagerism if you didn't attribute the translation to its original source. It may or may not be a copyright or other violation, depending on whether the government has authorized public use and reproduction of that particular document or not. Most things like government reports are in the public domain, but other things, such as books published by public universities, may be copyright protected. So you have to determine whether the doucment is in the public domain or not.