I am not sure that "gospel truth" is a fair characterization.

Anonymous IRC person has provided verifiable details that strongly suggest he or she had access to Linode administrative systems. Fyodor's post to nmap-dev supports the notion that customer nodes were accessed as well.

Linode has provided no details or evidence of anything.

I don't think one has to take that IRC log as gospel truth to be reasonably concerned about the security of their data stored by Linode.