CNAME and other data?

[Mark Damrose]

In troubleshooting a problem in another forum, I ran across this situation.

$ dig ns.rlgsc.com @ns1.speakeasy.net

;; ANSWER SECTION:
ns.rlgsc.com.           172626  IN      A       66.92.111.10
ns.rlgsc.com.           11839   IN      CNAME   gatekeeper.rlgsc.com.
gatekeeper.rlgsc.com.   12000   IN      A       66.92.111.10

This server is listed in the NS records, but is lame.  It also allows public
recursion.  The A record is the glue record retrieved from the GTLD servers,
and the CNAME was from the actual zone data.

I know that NS records shouldn't refer to CNAME, and will advise the domain
owner.  I was surprised to see both an A and CNAME returned from cache.

$ dig version.bind chaos txt @ns1.speakeasy.net

;; ANSWER SECTION:
VERSION.BIND.           0       CH      TXT     "8.3.3-REL"

Is this a known side effect of an NS points to CNAME misconfigured domain,
or is this a bug?