There used to be an exemption to the ADA rules for commuter carriers. The aisle chair doesn't fit down the aisle. There was no way to remove people down the stairway, either.
I think there is some serious bs going on in this story. No one lets a man crawl across the tarmac. Still, the damage is done from a PR standpoint.
I read the article this morning and many of the comments raised the BS flag, too.