You're as hard headed as it gets.
https://puu.sh/A9nuh/fec1395f95.mp4 <- Here's a video of myself against Ultimate Mastema with Wind.
Having D'art's HP gun should modify Sniper Shot, applying 2 instances of either Attack AND Defense reduction buff, but it only shows one instance.
You can see the damage I deal before and after applying Hraes' def debuff as well.
That video alone is proof enough that Nutaku is not only incompetent at the time of implementing things, but also unaware and highly mediocre to not fix a bug that shouldn't have been there to begin with.