This map includes inaccurate / very approximate positions, errors of 200 nmi or more are not unusual.
If no ADS-B / MLAT info is available but at least 1 receiver is receiving ModeS data from a hex, the aircraft is placed where the receiving station on average receives planes which do have a location.
Please add a disclaimer to any screenshots of this website or better yet just report that an aircraft was spotted in the approximate area WITHOUT using screenshots.