Yeah, there's been repeated public statements about they're not responsible if successfully-funded projects go off the rails and into the crapper.
Now, I can kind of understand that when you get behind the idea of Kickstarter as an investment model. But the average person does not exactly have venture capital experience, plus most kickstarters are an emotional sell anyway.
What will really kill Kickstarter is if the site really gets a reputation as being a big scam on a overall basis. If too many projects crap out or too much money vanishes, the site will be toast. Now that's not based around any one event, that's more of an aggregate thing over time. There might be some "significant failures" or lawsuit attempts that will punctuate things, but the real impact will be a gradual and collective shift in opinion that Kickstarter is just a con job instead of a dream factory.