So far this is one of the best reports of it I've found so far, with the follow up having a lot of details and sources of info.
first report: https://peakd.com/steem/@apshamilton/justin-sun-thwarted-a-white-knight-saves-the-steem-stolen-by-hf0-23-by-sending-to-bittrex

follow up after they talked to a lawyer: https://hive.blog/hf23/@apshamilton/pro-bono-legal-opinion-for-victims-of-steem-hf23-and-bittrex