A noble effort. George Mallory's body was found and positively identified in 1999. His climbing partner Sandy Irvine is still missing.
For many years Graham Hoyland wanted to believe Mallory made it to the top. In this article he posits a well-researched and cogent analysis of what likely happened based on all the evidence. If you are interested in this topic it is worth a read.
Mr. Hoyland thinks he came close but fell while he was roped to Irvine. There is evidence of 2 falls and the second fall was fatal. George Mallory almost certainly did not reach the summit.
No mention is made of the Hillary Step. It is located between the South Summit (28,500′) and the true summit (29,035′). It is often described as a nearly vertical rock face with a height of around 12 metres (39 ft) at 28,839 feet.
A 12 meter vertical face just below the summit proved to be an extremely difficult barrier for Hillary and Norgay on their historic summit in 1953. I have read about Mallory over the years and never seen it mentioned. So they must have taken a different route that did not include the Hillary Step.