It’s a software world. And because of software, it’s a soft world in a different sense, in the original sense of the word: it changes its shape easily.
The accuser is also failing to recognize that there is, in all likelihood, a finite number of ways to “solve” any given task. Is it so completely unbelievable to assume that another talented individual happened to arrive at a similar conclusion as themselves? It’s just as easy to give someone the benefit of the doubt as it is to assume the worst of them.