They aren't lending the physical book and the digital book simultaneously; there's only ever one "book" lent. To my mind this is materially different from sites like Anna's Archive.
The law is the law, and the court doesn't care about your opinion. They broke the law.
Seriously, I don't understand the reluctance of some to admit this. It's almost like the rule of law just doesn't exist for you as long as it's a cause you care about. Even more puzzling is the idea that you should just wantonly break the law in a way that drags down good institutions with you as if your own personal battle with bad law is more important than anything else. It really isn't, and I wish some of you would accept that fact rather than trying to one-up each other on the internet. It's not helping anybody.
Civil disobedience is breaking the law. Are you suggesting that Rosa Parks should have sat in the back of the bus?