Just because you have no evidence, does not mean it does not have a cause.<quoted text>
Since you have not defined the concept of 'x causes y', I guess we are at an impasse. There is no evidence of a cause for the time of a muon decay. We have a predictive theory that describes muon decay as probabilistic with *nothing* different just before the decay from any other time. And you have nothing but stammering that there *must* be a cause.
It operates within a theoretical system which means that it is affected by other elements.
Your argument basically is the same as the flat earth argument.
We cannot prove the earth is not flat, therefore it is flat.
May I suggest you have assumed that, because you need to maintain your worldview and justify a universe that does not have a first cause...