I read the article
But he is contradicting himself.
In the comments, he says he the project by himself at home.... and even then says he did it with the company's support - indicating some level of company involvement.
In the article, the guy refers to releasing back code, make a contribution, - was done by "we" - i.e. him and the company. THAT IS AN ADMISSION of the their ownership interest.
It's pretty clear the company would believe they had some involvement, and probably ownership of the code. And he believes it too -- And even when later the guy tries to remove the company's involvement from development, he does equivocally and in contradiction of his own earlier statements,
I've noticed several design suggestions in your code.