Hills - a dead end?

[Araminta]

They married in Victoria in 1863 and went to NZ a few months later.

[KathNZ]

"The only source for John Hill's parents' names is that marriage certificate: Henry Hill, builder, and Jane nee Lloyd, both died 1844 . "
How do you know that John's parents died in 1844 ?

[Araminta]

Death years of all four parents are listed on the Australian marriage cert.
The offspring may not have remembered all the dates correctly, but it's the only source I have for this info, having failed to find the families in England and Ireland.