The reading and the lecture talk about the mystery of the "ghost ship" Mary Celsete. The professor casts doubts upon the explanations stated in the reading.
To begin with, the professor doesn't agree with the theory of mutiny mentioned in the reading. According to the reading, Captain Briggs was murdered by his crews for his rigidness, and the ship was abandoned then. The professor objects the theory by stating that, first, Caption Briggs was respected, experienced, and with good reputation, and second, no crew took personal belongings with them when they abandoned the ship, which puts the credibility of the theory at risk.
Secondly, the professor disagrees with the theory of piracy stated in the reading. He thinks sound evidence is lacked to substantiate that Mary Celsete was actually pirated by the ship which claimed to find it. He further supports his opinion by the information that the captain of the so-called pirate ship was the friend of Captain Briggs.
Finally, the professor raises his explanations of the mystery. He thinks the ship was probably abandoned suddenly when it was found to be at the risk of explosion. He mentions the barrels carried on the ship, and postulates the leakage of alcohol from these barrels made the Caption very nervous. Upon the sight of fume, the Caption thought the ship was going to explode and ordered to abandon the ship in a hurry. Many of the crew were drowned or suffered from hunger to death.

There is a lot of theories what has happened to the Mary Celeste ship. However, most of them are weak and doubtful.
One of the suggestions is that the ship's crew didn't appreciate its captain much. Consequently, a sedition exploded aboard, and Benjamin Briggs was killed. The crew throw the dead body overboard and escaped on lifeboats. Though the found nine barrels of alcohol being drunk up support the possibility of these events, the lecturer refute the incorrectness of the theory by providing the evidences that, actually, the crew liked Benjamin Briggs. The captain was famous for his good reputation among the ship workers, so that the possibility of the mutiny was minute. Moreover, the lecturer disprove the theory the founders of the ship pillaged it and killed all the people on board. He says they were the friends of the captain and, if they did so, they couldn't have get rid of evidences they committed the pillage.
Moreover, the lecturer provides the most plausible explanation for the ship's enigma. The crew, as known, had never experienced the transportation of alcohol. And, therefore, it was much scared when sailing with it to Italy. So on its way to Genoa, the alcohol leaked and its explosive fumes exuded. They caused a fire on a ship, and the scared crew had to abandon Mary Celeste. This kind of the explosion didn't damage the ship much, so that's why it remained in its ordinary condition. And the reasons that the crew wasn't found later may be that they drowned, or got into the storm, or died from the hunger.
To conclude, the reasons that the Mary Celeste was found empty because of the crew sedition or because its founders pillaged the ship are weak and controvertible. The most believable version is that there was a fire on the ship.

The reading passage and lecture mainly talk about the “MARY CELEST ghost ship”, as well the theories that involve the missing ship.
The reading passage provides a possible theory that might happened aboard the ship. This theory brings about the possibility of a sort of mutiny or piracy, which had killed the Captain and his family as well the whole tripulation. After that they might discard the bodies and runaway in the small sailing boats.
Another theory presented in the reading passage is the crew that had found the ship close to Portugal area killed all the tripulants aboard and claim the rewards for finding the missing ship.
In the other hand the lecture, however, contrast the theory of piracy. The lecture mentions the Captain was an honorable man, with a highly reputation and the marines would never take their belongings.
The lecture mentions the possibility of the crew might runaway from the ship, probably they have seem fumes, from the barrels of alcohol, they got to in panic and left the ship.
However, studies were done proving that they fume were not burn down the ship.
In addition in that era the Captain did not have enough experience in fire and because these reason they abandon the ship.
Moreover they could have died for 2 reasons:
They left in a very small sail boat; they might have lost in the sea and drawn.
They might die by exarvation.

The lecture and the reading presents the issue of the Miystery of Mary Celeste. The professor refuses the explanation given on the passage and pressent a new one.

To begin with, acoording to the professor Mary Celeste's crew had a good reputation and respected their Captain. This contradicts the first explanation given on the text: motin.

Second, the professor states that the Captain who found Mary Celeste was a friend of Mary Celeste's Captain and that the crew made nothing suspicious. This cast doubts on the second explanation of the passage: piracy.

To finish the professor explains his theory. In his opinion people abandoned the ship because they were afraid of an explosion; Mary Celeste transported for the very first time alcohol, part of the crew probably become nervious when some of the alcohol licked. This will explain way they abandoned the ship quickly without taking any oftheir posesions.