There was some debate about whether we could address this as errata or not in the workgroup. The common definition of errata is errors that originate through the publication process, whereas errors caused by authorship are corrigenda.
According to the HL7 Publishing guidelines: Publication of corrections as Errata is used when it has been discovered that there is an error in the publication of a standard or DSTU, but it does not specifically identify the cause or reason why the error is present. This is a case of where knowing what was meant is more important that what it is called. Pulling out our process documentation helped my cause.
In this particular case, the error predates the Consolidated CDA guide. It was in fact caused by the merger of the Guardian relationship with other relationships (where family member, friend, and neighbor are sensible values). In that situation, a value set constraint associated with one participation was merged with another participation without appropriate inspection (I know how it happened because I chaired the committee where it happened). So, call this one a corrigendum, rather than an erratum.
We agreed on the call to address this as an errata with respect to publication, regardless of the cause. It's pretty clearly an error when the most common case needed for documenting guardianship comes from outside the set of allowed values. From the implementer perspective, what we really care about is that it be fixed, and I'm pleased that HL7 is doing so.