Liveweb doesn't differentiate between internal 502 errors, bogus urls and actual 502 responses.

Currently, liveweb records a 502 error to the arc if archive.org is down, dns is down, the url is actually invalid, or the server responds with a 502.

Best solution for now is to return a 49x or a 9xx error code to wayback and not record anything in the arc in the case of a 502 error.

If there is a more nuanced way to differentiate an actual remote server returning a 502 vs an error somewhere in our network, that maybe worth a look.