He should have offered refunds to anyone who asked and he wouldn't be in this mess. He could still mitigate damage to his ass by giving refunds even now, but so far I haven't heard of even one customer receiving their bitcoin back.
As bitcoin value increases it will become more and more in everybody's best interest to go after him for a refund.
At the end of the day, there is no evidence to show that they made reasonable efforts to try to complete the project (and there is evidence to the contrary), which points to a breach of the purchase agreement and grounds for suing. They've liquidated the company with a load of undeclared assets that the UK Government is going to be interested in, I'd love to see what financial statements they actually released and where they stand with HMRC, the company director was arrogant enough to post photos of himself and some of his ill-gotten gains before vanishing without a trace... surely these guys don't have a leg to stand on? People should be reporting this to their fraud authorities and pushing for a prosecution, in addition to taking out individual actions to reclaim their investments.
ICO frauds will just continue to darken the crypto arena until everyone starts taking action and the legal framework gains experience of dealing with these scams.