The law is not a set of simple rules and the rule of law is not - and arguably cannot -be reduced to a Turing Machine evaluating some formal expression of said rules.
A theme of mine for some time has been how dangerous it is to junp to conclusions about the extent to which the process of law - and its expression in the laws themselves - can be looked upon purely in terms of a deductive logic system in disguise.
Laws, contracts etc. often contain ambiguities that are there on purpose. Some are tactical. Some are there in recognition of the reality that concepts like "fairness" and "reasonable efforts" are both useful and unquantifiable.
In short there are tactical, social and deep jurisprudence-related reasons for the presence ambiguity in laws/contracts.
Trying to remove them can lead to unpleasant results.
Case in point : the draining of millions of dollars from the DAO. See writeup on Bloomberg : Ethereum Smart Contracts