When Ferocious is fighting the gladiators in the arena there are several shots where his stunt double has obviously replaced Robert Newton.
The Christians sing "Onward, Christian Soldiers" - a hymn published in 1871.
One of the attendants to the Queen of the Vestal Virgins can be seen to be wearing a bra.
The Christians sing "All People That On Earth Do Dwell", a hymn whose likely origin is in the 1500s.