I’m a web developer, that is absolutely not how any of this works.
Their claim that the scripts are failing causing comments to be restored is not possible. When you make a request to a website the site returns a success or fail status. The scripts are getting success statuses, the users are manually checking and seeing that their posts are deleted and then they reappear later. This means there is a mechanism between step 2 and 3 being run by Reddit affecting an already completed action.
Don’t comment on stuff like this unless you have any idea what you’re talking about.