>I thought that there was no family tomb, so Joseph of Arimathea offered his family tomb for Jesus' burial
That tomb could have been used pre-Resurrection, and this new one post-resurrection (i.e. years later), it does not necessarily rule it out. But these folks have a whole lot of proving to do before I accept their theory.
But there would have been no burial after the Resurrection, because Jesus ascended directly into heaven.