I haven't heard from them about any developments after they disabled margin trading.

It shouldn't really be that much of an issue, nobody was selling at 10c and there were only buy orders at 10c. The only person losing out here is the person who executed these margin trades since he sold all his ETH at a lower price than he could have.

It could be possible that it's a bug on coinbase's side also, but we haven't heard from them at all about this.