I mean there's no way to "salvage" it, because buying $300 worth of books for intolerant book burning you don't really believe in does reveal you to actually have no principles and to want do a lot just to be liked.
The best thing to say is to explain exactly that and genuinely express that you understand it is a problem and you're working on it, which of course anon couldn't because there's no indication of this level of self-awareness.
But if they would, they might still be shunned, but it is very unlikely imo. Good people understand trauma and appreciate trying to work through it.
The problem is that the truth is pretty damning imo, like if they're able to participate in actual book burning they don't believe in and basically burn $300, I wonder what other dishonest thing they would do just to be liked. Not really something you want to be around.
I'd only be fine if they honestly explained that they knew it is a problem and they're trying to fix it.