They said: "not apply to open-source software developed or supplied outside of a commercial activity". As I understand, if you work making more than 90% of you

They said: "not apply to open-source software developed or supplied outside of a commercial activity". As I understand, if you work making more than 90% of your income as gardener, but on free time develop OSS, you will guaranteed not liable. But if you are professional software developer, and make for example 50% of your income from software, you will need some powerful proof, that OSS from case and made by you was not part of commercial activity.