Hi there,
May I suggest that if the Queensland marriage was celebrated by a clergyman, that the clergyman recorded all the details in his own parish register. The Qld certificate will note the name of the clergyman and the denomination and the location for the marriage. Likely the names of the parents of the groom and the occupation of the groom's dad will be on that original register. If the person providing information for the death registration had relied on the information held by the Qld BDM as per that marriage certificate, then that may well help to explain the deficiency in info on the death registration.
NSW civil registration system was established 1856. Queensland was hived off from NSW in 1859. Probably the Qld BDM civil registration system copied the existing system.
So, hopefully it will be a matter of determining where the clergyman's register is currently held. Likely that will be with the diocese or state headquarters for the denomination of the clergyman.
Church records are not public records, so you may need to ask for access, and likely you may need to wait until a volunteer has looked up their record. If you were to provide a copy of the Qld BDM marriage cert, there may be clues on it for the volunteer to use in their look up efforts.
JM