We found several examples of records where the length of the authors list and that of the ORCID arrays (_pub, _user, _other) is different.
In some cases also the size of the orcid arrays is inconsistent, with a _pub array longer than the others.
We are still investigating the issue and we should be able to provide a long list of bibcode to verify, in the coming days.
A first example is 2014ASPC..486..203M
Best regards
Claudio