Character mistake: Upon hearing that Lister, Kryten, Cat and Rimmer have travelled from Albion - England - to India the woman in the market expresses surprise that they have travelled "halfway across the known world" just to buy lemons. In 23AD travelling from England to India was all the way across the known world. The Americas, Australasia and China were completely unknown at the time.
Character mistake: Surely, a know-all like Kryten would know that although lemons are not native to the Middle East, Babylonian traders imported lemons into what was then Judea some five hundred years before Christ was born, and by 4BC, they were quite common in the area, albeit as a pricey imported delicacy. The Dwarfers wasted half of their epic overland trek.
Factual error: At the very end of the episode right before the Dwarfers sees Jesus and Judas, there is a plastic cup on their table. The episode is set in 23 AD.
Audio problem: When they are chasing Jesus through the market, Lister's mouth is out of sync when he's shouting. (00:26:15)
Answer: It's Queen Victoria, someone any Englishman would recognize, and needed no introduction.