While it is possible to get infected with malware by clicking on a link, I would not take what Side Chain says at face value without evidence. He may have hacked bitcoingirl.club, but I would not assume so without evidence.
This should not distract from the very troubling messages that were disclosed. From their own description of what they were doing, some people were “shilling” for SB, and asked at least one person to lie about why they were taking a stance in favor of a company they were receiving payment from.