Comment to self: This is a rouge CS created during a crashed JOSM sessions while uploading a 1300 node CS set. Lesson to take away from: When JOSM upload/session crashes or comp has power faiil during upload and restarting JODM to recover the data not yet uploaded, check if a partial CS was entered into OSM. Two possible solutions. 1) Backout/revert the CS resulting from the crashed/partial CS upload and then retry to original upload. 2). Run a JOSM Update Data or Update Modified to fetch any node IDs that may have been created during the failed upload. If you dont you could likely end up with orphaned nodes, in this case exactly 1000. Saves lots of time the next day not having to delete these duplicate nodes from the system.