the U.S law re libel is New York vs Sullivan-1964 last I looked- the standard for libel re a public personality is "reckless disregard for the truth".

Bob is not a public personality (that would be well known actors etc who have profited from fame) so the standard for libel re these CEO's is somewhere between simple negligence (the standard for a private individual) and reckless disregard.
js and lucky and most bashers completely violate that standard but somebody has to sue them to enforce the standard-and a post by Bullit69 talked about this a long time ago-its a matter of priorities-how much of your life and money do you spend suing these people-these bashers know that- so they consider they have freedom to operate w impunity in penny land.