I'd rather hear them talk about the presence of coffins themselves. My understanding of Jewish burial customs of the time is that coffins weren't used; certainly not in a "cave" type of interment.
Yeah. I always thought that Jesus was wrapped in a shroud before placed in the tomb. (Shroud of Turin)
I believe they used ossuaries, didn't they?
The burial practice of the period in Jerusalem was to place a body on a niche or shelf in the tomb to allow it to naturally decompose. After about a year, the bones were collected and generally placed into a pit in the center of the tomb with all of the ancestors' bones (from which comes the saying "gathered unto his ancestors). The niche or shelf could then be reused. A wealthy person's family's might have a separate stone ossuary (bone box) made and to have the bones put in but that was comparatively rare.
For Joseph, a native of Galilee or perhaps Nazareth to be buried in a Jerusalem cemetery would also be unusual. Jewish people believed the body needed to be placed in the grave before sundown of the day of death and then the body could not be disturbed except for the ritual gathering of the bones a year or so later. Carrying Joseph's body or bones from his burial place would be highly unusual.