Wrong. Water can indeed be heated beyond its boiling point without actually boiling, a process known as superheating, and this is much more likely to occur in a microwave than a stove due to the fact that a microwave heats water more evenly. It is a well-known hazard of microwave cooking.
"Homogeneous liquids can superheat[32][33] when heated in a microwave oven in a container with a smooth surface. That is, the liquid reaches a temperature slightly above its normal boiling point without bubbles of vapour forming inside the liquid. The boiling process can start explosively when the liquid is disturbed, such as when the user takes hold of the container to remove it from the oven or while adding solid ingredients such as powdered creamer or sugar"
