I'd say rather they didn't know what they were doing and in the processed they managed to mess up your website.
this was also my guess that the hired worker only got hired because he badly need a job but dont have an adequate knowledge on the said task . its waste of oppurtunity for the other workers that really deserve this job .
Or you might have got involved with crypto haters.
this chance is low to have them because if they are just a hater they wont do a plan like this because its time consuming . they can do a less hassel task like creating dummy account on a crypto forum and talk against it