Scammers Using Validator To Scare

Hi,

I've received a report from a family member who received an
unsolicited call from someone who pointed them to the w3 validator and used
the fact that their service provider having errors on their site was
evidence of them having malware on the router and that they should be
granted access to "fix" it.

So I thought I'd email and see if there was a minimally impactful solution
that could reduce this negative behaviour while not requiring much work or
change in the existing tooling.

I wonder if it would be reasonable and wise to add a small disclaimer to
the top of the results saying that the errors displayed are not evidence of
malware or something similar?

The page in question they were asked to lookup was this:
https://validator.w3.org/nu/?doc=https%3A%2F%2Fwww.virginmedia.com%2F

And for a non-technical user directed to the site, it does look scary.

I'm not expecting any concrete action, just wondering if there's any
reasonable way to address this?

- Folcon