Final answer:
The statement is false; a water leak is a material fact because it can lead to serious damage and affect property conditions.
Step-by-step explanation:
The statement that a water leak inside a wall isn't really a big deal and thus not a material fact is false. A water leak can cause significant damage over time, leading to mold growth, structural damage, and even electrical hazards if left unaddressed. Therefore, a water leak inside a wall is indeed a material fact when it comes to property conditions, especially in real estate transactions.