To me, it's not the chance of somebody getting in trouble that worries me, but rather the blatant disregard and disrespect for intellectual property rights.
Intellectual property rights aren't holy scriptures. Not every right should be respected and it seems dishonest to play that card. It's the same idea as law isn't moral just because it's the law. It can still be unjust and immoral, depending on the circumstances. To follow a hard line of always adhering to the law without any regard for the consequences or context can lead to bad outcomes.
That's all fine and good but Xerox is no longer in the business of selling this book and does not suffer any harm from the reproduction, neither do the authors.
It's a bit like public libraries, which also 'hurt' book sales, and there the books might even still be in print. The Smalltalk 80 Blue Book is an important part of computer history, the more copies there are of it, digital or otherwise the better.
