first of all, i'd argue that speech can be violent when it normalizes violence against a group of people or when it attempts to maliciously reference violence of the past that is closely related to the word in question. calling black person the n word is a violent act because it is using violence that is associated with that word in place of the violence associated with that word. in the same way, using the more offensive words with malicious intent is an attempt to renormalize violence against them - violence that was often used in tandem with the words of violence. of course, there weren't mass lynchings of people with disabilities (none that i know of at least), but institutionalizing and informal brutalization of people with disabilities has been used, as i said before, in tandem with these words to such an extent that saying them carries the violence of the past with them.
i dont know how you think i haven't been defending the claim of the author because that's what this whole conversation is about.
and yes, i'd agree with you that people are violent when acting in righteous anger. i'd argue that certain words have adopted this anger by virtue of being used with this anger to such an extent that they can be used in place of physical violence as a way to silence an individual. we see this with racial slurs too: https://www.nytimes.com/2018/09/21/us/racist-remark-reactions.html https://www.kuow.org/stories/man-shouts-racial-slurs-seattle-starbucks-silence-deafening this is a book but i'll still share it: https://www.amazon.com/Violence-Abuse-Lives-People-Disabilities/dp/1557661480
and, in finding these instances, i found the same list in the blog published by Augsburg College: http://web.augsburg.edu/english/writinglab/Avoiding_Ableist_Language.pdf
while writing this, i saw your other message about "prick", so i'll include it here. No, i'd argue that prick is not violence because nobody was yelling prick at you as they were beating you senseless on the sidewalk for just being a man or any other systemic violent act associated with being a man. again, that's as far as i know but it's pretty safe to say prick isn't a word that is associated with historic and systemic violence, and it, therefore, does not carry with it that historic and systemic violence.