Bug, Tristana ult ignoring banshee's veil on secondary targets

I had a banshee's veil and got knocked back by Tristana ult. I figured out that it was because my teammate was ulted, and I only got hit by the knockback as a result. This was in spite of having the banshee's veil passive up. I had the spell shield up both before and after getting knocked back. Has this happened to anyone else? This seems like a bug. Is this intended?