Bowser's right on this one.
Same basic idea, which probably occurred to about six thousand people separately. No phrasings in common. No plagiarism.
Besides, you have to know Bowser's personality. He's all about the internal voice and his own ideas, with an almost Kryptonian resistance to outside information.
Definitely not the type who would grab somebody else's specific ideas and take them for his own. In fact, he's almost allergic to it.