User we are talking about is JamieCarollKrol. It shows 2 edits according to CentralAuth, but when going to the contributions of this user on MediaWiki.org nothing can be seen (according to Trijnstel and Matiia, both stewards). It's also not hidden in some way (eg. RevDel or oversighted).
Something fishy is going on.
When a user is expected to have no deleted contributions, Special:DeletedContributions should show the message nocontribs, but that message is not shown on https://www.mediawiki.org/wiki/Special:DeletedContributions/JamieCarollKrol. It shows the output of an empty pager instead. Compare to https://www.mediawiki.org/wiki/Special:DeletedContributions/MainframeBot.
I'm attempting to find out where these edits have gone using Quarry, but so far no luck yet: https://quarry.wmflabs.org/query/16995
I checked on the database master, there are no rows in the revision nor archive table corresponding to their user id (12188407).
There's an HTML comment saying <!-- Could not format Special:DeletedContribution row. --> (see DeletedContribsPager::formatRow()).