In all honesty, this one I disagree with holding Apple liable (unless it can be shown that they were involved in ATT's pricing scheme) - ATT controls their data plan, and unless there is compelling evidence that Apple conspired with ATT to bait and switch the available plans, Apple is technically a victim as well as they
probably made the marketing and plan options based upon what ATT offered at the time of release.
I'm not sure of the dates, the article may have been a bit misleading - but it mentioned:
On June 9, 2010, a consumer who purchased an Apple iPad with 3G capability and signed up for an AT&T data plan filed a nationwide class action lawsuit against Apple and AT&T for fraud and misrepresentation.
The change in ATTs data plan took effect on June 7th - which means if the user purchased on June 9th, the change was already in place and well known which means the person seems to have been simply trying to take advantage of a change in place that the user probably would have already been aware of.
I'm not saying I agree with the change in terms - honestly, I think ATT really did a negative thing here, especially for the way iPad users were marketed to based upon ATTs offerings at the time the iPad was released and future release plans announced (since if I recall correctly, ATT changed its pricing a month after the iPad 3G was released and several months after the release date was even announced for the 3G version of the iPad).