Is that how it works? Once you own shares, you're obligated to pay for whatever unplanned mishap occurs? The fact that the aircraft got stuck on a loch without a slipway or handy beach is not really something that they were planning for.
Fortunately, a lot of people have been generous and they are close to reaching their goal. Any extra funds will go towards overhauling the engine that didn't want to go anymore. See here:
https://gf.me/u/y5mf94