I'm tempted to say it's a bug, if only for the fact that assuming WW's other human-looking scores are legit, it hardly seems worth hacking scores on maps like those, which should be well within his abilities.
Perhaps it's as AirCoN suggested, which is that the bug is related to replay compression (rounding on hit timing). Although, assuming that the Pony Swag and Shinto Shrine replays are part of the same bug as the Airman replays, it doesn't seem to be restricted to only maps with BPM multiples of 50 (since Pony Swag is 120/180 and Shinto Shrine is 160/240).
Perhaps it's as AirCoN suggested, which is that the bug is related to replay compression (rounding on hit timing). Although, assuming that the Pony Swag and Shinto Shrine replays are part of the same bug as the Airman replays, it doesn't seem to be restricted to only maps with BPM multiples of 50 (since Pony Swag is 120/180 and Shinto Shrine is 160/240).