I think we need to be careful about the domains that their registrar name server and zone’s NS record don’t match.

Based on the following explanation in this link, we might encounter problem if Registrar’s name server are different from zone’s NS record. Because according to it, the registrar’s name servers (glue records) point the resolver to the zone’s NS records (authority records) which then they are used to resolve other records.

“The resolver will take this delegation response, resolve the host name of a NS record if necessary, and proceed to query the DNS server to which authority has been delegated. This process may repeat a number of times if you have a deep delegation hierarchy, but eventually results in a query response with the “authoritative answer” flag set.”

 http://serverfault.com/questions/526278/clarification-of-why-dns-zone-files-require-ns-records

 Search on this topic is a bit difficult because of ambiguity and similarity of terms, but I found the following useful in the same order

http://serverfault.com/questions/526278/clarification-of-why-dns-zone-files-require-ns-records

http://www.linuxquestions.org/questions/linux-networking-3/dns-ns’s-in-registrar-vs-dns-ns-records-729119/

https://www.quora.com/When-a-registrar-primary-DNS-and-secondary-DNS-are-all-different-which-NS-records-should-exist-where