DCO signed off failing for one of PR (commit)

[PraveenPenguin]

Hi, In one of Our Repository DCO is failing as signed-off of the user, As user did change his commit signature with different user email-id and did his primary email-id setting pointing to a new email address but still in DCO complains about signed-off is missing with old email id

REPO : https://github.com/open-power/op-test
commit (PR): open-power/op-test#678

DCO app run link : https://github.com/open-power/op-test/runs/5622527719

failure log is :
Commit sha: 2aa1062, Author: Sachin Sant, Committer: Sachin Sant; Expected "Sachin Sant sachinp@linux.vnet.ibm.com", but got "Sachin Sant sachinp@linux.ibm.com".

[PraveenPenguin]

Any input will be a real help

[sacsant]

Is there any input on this issue?

[mwasilew2]

potentially related to: #39

a more verbose error message would help here (it's unclear from the message where the expected email is coming from)