Why were Protestants allowed to help translate the New American Bible?

Do not be so picky; Protestants are not Arians or Nestorians. It is a mixed bag. On the one hand they are Protestants and do not appreciate our Catholic doctrines; I know of no Protestant who would use 1 Corinthians 3:10 to 17 as a defense of purgatory. On the other hand, many of these men know their Greek and Hebrew, which is the language of the Bible, and they can give you nuances most Catholics do not know, while many Catholic scholars who do know the languages are liberals who use that knowledge to tear down traditional doctrine. So sometimes I would rather have a Protestant scholar who knows what he is doing than a Catholic scholar who barely knows the biblical languages. It all depends on the quality of the individual. As it happens, the New American Bible is probably one of the best translations we have ever had; whenever I compare it with the RSV, the NASB, the NIV, or the NRSV, it holds up very well, both the 1971 and the 2011 versions. Where you can go wrong is the commentary, because the NAB is annotated by Catholic liberals who do not believe the history of the Bible, treating Genesis creation, Adam and Eve, the Tower of Babel, and Jonah as fantasy, and they will let you know it in the notes.