The AND gate has that a floating output when it should output FALSE. Actually, it should be grounded to indicate false. What is shown is a device that is tristated or true. The OR gate has a similar problem.

The explanation of the NOT gate is worse. It shows a "waste basket" that "discards" current, according to the explanation. I don't know of an electronic device called a "waste basket," but is sounds like its talking about a ground. But if it's a ground, the transistor will create a short circuit when it's closed! This gate would start a fire (perhaps in the "waste basket"!) if it were given a true input! There is a resistor, but it's in the wrong place.