User blog comment:Omega natsu2/Episode 187: Frog, Review./@comment-24895561-20140621052807/@comment-7418318-20140621100418

In Hades defense, when Wendy disappeared, her clothes were left behind, which makes "classic" teleportation or simple dodging very unlikely, since those would also have transported the clothes along with her.

Apart from being arrogant and over confident like you already said, Jiemma also had no reason to think that Minerva might betray him. Even when she stood in his way when Natsu attacked their inn, she still did it for the good of the guild and his own good too. In other words Minerva played it very well. She always seemed to act like the good, loyal daughter and then acted at exactly the right moment, without him ever considering the possibility of betrayal by her.

If you consider it a betrayal in the first place, since she just acted exactly the way he taught her.