If hyperbole is an exaggeration, the opposite is a type of understatement.
An exaggeration is defined as a statement that represents something better or worse than it really is. In contrast, an understatment is a statement that represents something being smaller, worse, or less important than it really is. The two are opposites.
Answer: you would just calmly reply yes that may be true but if it is something rude or not polite to say then kindly ask them to please keep that comment to themselves