Intellectual property is a myth.
The law makes no mention of intellectual property, and the kinds of things usually referred to as intellectual property are not protected by property law.
Intellectual works are protected by copyright law, trademark law or patent law. They are not protected by property law, they are not property, they cannot be stolen, and those who use intellectual works in a way that violates applicable laws are not thieves.
Your friend might be potentially liable for copyright infringement, but this is actually an interesting question. That is because strings of numbers are considered uncopyrightable, in turn because they are naturally occuring things and anybody could have come up with them.
That would be a good question to ask of a lawyer. It is by no means clear cut.
Certainly, your friend removed no physical property from the store, so he is most certainly not guilty of anything under property law. Therefore he is most certainly not a thief.