Not a teacher. You're wrong. It was said he was buried as a complement of what was coming next, that is, the specification he was buried in a tomb, which is there to this day.
It just completed the logic of the facts expressed. Would be weird if it said the person died and then jumped out of nowhere to saying he was in a tomb. Saying he was buried fills the gap and makes it easier for the reader to follow.
Student or Learner