User blog comment:Omega natsu2/Episode 187: Frog, Review./@comment-24895561-20140621052807/@comment-4829046-20140621095720

Still, if he truly knew all the properties plus his own Daughter's magic, he would have been able to tell his magic didn't hit. It was a meager low-powered spell. Then again, he was super cocky and arrogant so makes sense for him to not think much about it. If it were someone like Hades, he would have noticed.