The distance between Asua and the rhinoceros changes between shots, depending upon whether Asua is in the shot or not.
When the escaping refugees attempt to evade the slavers by stampeding a herd of elephants, at various points the elephants are Indian elephants (smaller ears). Then in long shots, African elephants (large ears) are shown.
The rhino seen in the distant shots has a much bigger horn than the rhino the charges them.
There was never a Royal Suffolk Regiment in the British Army, though there was a Suffolk Regiment (so named in 1881). The Suffolk Regiment did not serve in Egypt and was not part of any attempt to rescue General Gordon. The First Battalion was in India and the Second Battalion was in various postings during this period. The Second Battalion did get posted to India in 1892, well after the events of this film.
The end of the film heavily implies that the two-day-late relief force for General Gordon recaptures Khartoum. In reality, the relief force discovered the city already taken and the Mahdist forces strong, and were forced to retreat, leaving Sudan to the Mahdi. Khartoum was retaken only 13 years later in 1898.
Baker is mistaken for a major by Miss Woodville and Murchison as he supposedly is wearing a major's jacket. However the jacket has the three pips of a captain on the epaulets, rather than the crown of a major.
When the group are hiding from the Arab slaver barge, they take refuge in the undergrowth. A snake is seen to crawl over Sylvia Syms. The snake is a Red-Tailed Boa Constrictor, native to South America, and is not an African species.