We're looking into a few cases where mobile live streams appear deleted if metadata (title, description, tags) or change privacy setting (public, unlisted) is edited while processing. It shows: "the video has been removed by the user". Thanks for the reports–updates to follow!
Gee your looking into the problem I reported months ago after losing several livestreams. That's nice. It's a shame when I reported it I was treated like an idiot and told I absolutely had to have deleted the streams myself.