Those failures has to be checked:
25	Returning of answer
26	Returning of name error
28	Encounters a CNAME
32	Analyze the response (delegation)
33	Analyze the response (caching delegation)
34	Analyze the response (caching CNAME)
36	Analyze the response (answer is invalid for caching)
51	Message compression
52	Not depend on response in order
54	Invalid response (RRs are incorrectly formatted)
56	Invalid response (ID does not match)
58	Caching several RRs of same type
61	Time out of cache
65	Caching of temporary failure
67	Differing TTLs from authoritative source
69	Caching of name error (NXDOMAIN)
72	Caching of no data (NODATA)
76	Resolver cache a server failure response
79	Caching of dead server indication
82	Caching of SOA record
87	Responders don't understand OPT RR
89	Returning of answer
90	Returning of answer (w/o Additional Data section)
91	Priority comparison
92	Priority comparison (round-robin)
93	Weight comparison
94	NXDOMAIN