Answer:
A Law must hold within its realm of jurisdiction.
Example: Newton's Laws of Motion are always found to be true at non-relativistic speeds.
At speeds where relativity becomes important Newtons Laws (in particular
F = M a) are not necessarily true - but, the relativistic equations must agree with Newton's Laws at non-relativistic speeds.
A large amount of evidence is necessary to support a Law but in itself is not necessarily true.
Quantum Mechanics has been found to agree with results, but there are different theories as to why this is true - even Einstein did not like Quantum Mechanics as formulated because it deals in probabilities