Auditors and thermometers

Martian lands to plunder, pillage, and burn. The Martian goes up to the owner of the first house he sees and says "I'm a Martian just arrived from the other side of the solar system. We're here to destroy your civilization, pillage, and burn. What do you think of that?' The owner replies "I cannot express an opinion based on a hearsay evidence, I am a Chartered Accountant"

The auditors have taken an inventory of thermometers held in a warehouse, in summer. The thermometers will be exported out of the country in January, and are kept under lock and key. In December, auditors ask management to redo the inventory count. The management is surprised "Why? Nothing has changed." Auditors tell them "The inventory is overstated, in summer there is more mercury in the thermometers."