They (the 2017 series) still show up when you do a manual search on the 2002 series.
Because they use the same name, Sonarr has no way of knowing they are for a different series, nor does your indexer when they both use the same name.
They made a mistake, it’s not incompetence. Like I said it’s been nuked and should have propers/repacks out to resolve it and future episodes shouldn’t be a problem. It should only be one episode that is wrong, unless the p2p groups use Taken
instead of Taken (2017)
which will probably affect WEB-DL releases.
No, because it would break the 2002 series, which takes precedence as it was there first, it’d also cause the episodes from the 2002 series to appear under the 2017 series if the search relies on the title.