From Arc's broader statements made at the time, I'm not sure they would agree with your first statement, or agree that there _is_ a neutral usage:

> “In our culture, `retard’ and `retarded’ carry a lot of baggage from the days when people were institutionalized in large state facilities,” [...] They don’t deserve to be treated in such a dehumanizing way.”

> Leaving aside the movie’s offensiveness or lack thereof, the uproar also serves to highlight the evolving standards of acceptable terminology [...] “Adults with retardation self-advocated. They clearly told us that the use of the word `retarded’ was very hurtful.

https://www.dailynews.com/2008/08/13/some-give-tropic-thunde...

FWIW, I don't necessarily agree with them in totality -- I have various disabilities and have zero issue with "disabled person" or "the disabled" (unlike the linked article) -- but linking to Arc doesn't appear to support the use of "retarded", even where the intent is neutral.

Thanks for clarifying. Fun fact, in the years since "person-centered language" ("person with X") has now also fallen to the euphemism treadmill, as modern advocates say it stigmatizes the disability X by separating from the person as a modification, instead of accepting it as part of a respected whole person.