Oooh, well on a defensive Pokemon it's almost always a good idea to maximize HP, unless the Pokemon has a draining move (recovers a larger percentage of health). HP EVs basically count toward both defenses, and when attacks hit hard, defense stats don't help as much as a few extra hit points. For example, I also calculated for a flawless Musharna with all the EVs in defenses. It would've taken 3 less damage than mine, but it had 31 less HP with which to take that damage. ^.^