Is it possible to deduce that the law of conservation of matter and energy is true because we have no evidence to the contrary? Because it's only based on 100% of human observation? Because not one human has observed evidence to the contrary?
It is violated on the quantum scale provided the violation is within the limits of the Heisenberg uncertainty relationm ie not directly detectable. But this violation does have observable consequences, e.g. quantum tunnelling. So in effect violations have been observed.
Note also that in the classical world, there were two separate conservation laws, conservation of energy and conservation of momentum. These were merged in relativity because they can individually be violated in relativity, but not in aggregate. In the 19th century, someone could have made your argument based on energy conservation - and they would have been wrong.
This shows the danger of induction. In effect I'm saying that we can't use induction to justify any physical law. How can we know that it will apply in all circumstances? We can't. We believe (or at least adopt) theories because they provide deep explanations for things, and are consistent with evidence.
In this case you've not only used induction but you've made an unjustified generalization. From 'by humans' to 'by intelligence'. We have no evidence of any intelligence other than human, and that any other intelligence has created codes, so what justification is there for this generalization?
Also, there is no fundamental principle involved in your statement about codes. Conservation laws, on the other hand, are powerful vehicles for exploring physics, they correlate to the existence of symmetries, and so they have a powerful role in our explanations.
Your statement has no correlation to any deep explanatory principle.
I suspect your statement is designed solely to support your already-held beliefs. Do you know any people who hold your belief about codes who are not already believers in God?