While trying to determine which string of dental floss held the jar, they concluded that only the string holding the jar would have a different pitch and the rest would be the same. This is false in that it would require each string to be wrapped around the poles with the exact same tension initially and then the weight of the jar added to the one string.
You cannot electrocute a person with car battery as it's voltage is too low for that.
In the final scene, Elyes Gables accent slips.
Toby says that Mark is "nuttier than a jar of peanut butter", but botanically speaking, a peanut is not a nut but a legume. (This sounds like the kind of thing Scorpion members might know, by the way.)