I Survived the Destruction of Pompeii, 79 A.D.

Tarshis, Lauren. I Survived the Destruction of Pompeii, 79 A.D.
August 26th 2014 by Scholastic Inc. 
E ARC from Netgalley.com

Marcus used to be the slave of Linus Selius, a scientist, and his father, Tata, helped the man out with his studies. When the scientist died, Tata was sold, and Marcus' life at Festus' house in Pompeii became very difficult. Pompeii is seeing a lot of natural disturbances, and when there is a tremor in the market place that knocks an old lady down, Marcus helps her up. She warns him that dire times are coming and advises that he should "follow the hand of Mercury". When Marcus sees gladiators coming into town and recognizes his father among them, he is determined to rescue his father from certain death. The disturbances, as well as the appearance of a horse the two are able to ride, make this escape possible, but Tata feels compelled to go back to the town and let everyone know that disaster is looming and that everyone should flee. The guards don't take the slaves seriously and their freedom is again in peril. Can the two survive not only the volcano but also the evil Festus?
Strengths: I'm a huge fan of this series. The books are fast paced, exciting, and impart a great deal of historical information to reluctant readers. Pompeii is covered in our seventh grade social studies curriculum.
Weaknesses: Disclaimer: I taught Latin. There were some details in this book that struck me as not quite right. At one point, guests come to Festus' house driving a chariot. Chariots were used only in the military, as far as I know. Horses were not really ridden, as they were very hard to obtain and expensive to keep, which makes me think that Marcus' chances of finding an abandoned horse who was amenable to being ridden would have been slim. Tata was an educated slave from Germania, and it seems unlikely that he would have been sold as a gladiator, even if Festus had a grudge concerning him. Of course the guards wouldn't have listened to the slaves. I doubted the pair's ability to escape after ash started falling.

So I'm torn. This is a good story, and some of the details of Ancient Rome are good. Am I being too picky? Tarshis clearly did research, so am I misremembering details?

By the way, an excellent online resource for Roman life and culture, Mary Johnston's The Private Life of the Romans, is available at ForumRomanum.org.