In other words, if something is a fraud, that should be made self evident after you've proven the case that mistakes were made. No need to label it as "fraud"...in the same way that a funny joke should not be prefaced with "This following joke is very funny"
It is as easy as saying: "This graph is in contrast with this data...". If it is overwhelming, it is by itself, not by the adjectives.
It's not libelous, unless you're referring to legal definitions in specific repressive countries (such as the UK). Libel is a malicious lie. This is someone speaking their conscience.
There are other issues about your comment, but I'll start with just pointing out that your assertion here is false. A statement can be considered libel if gross negligence was involved, not just malice.
Perhaps not, but PROVING that it's not is expensive.
It looks like their plan for the future is a re-launch doing just that so let's see what they come up with.
Saying something is fraudulent is libelous, saying you think something is a mistake is just about as bad in the scientific world (the research is just as invalid) but does not carry with it a sense of judgement. Who knows whether something was a mistake or outright fraud, sometimes it is hard to tell the difference (see the certificate matter on the homepage right now).
Do not attribute to malice what you can attribute to incompetence works just as well in the scientific world. Having to retract a paper is no fun at all.