Unable to open bags during pvp

Is there a reason we are unable to open the build bags during pvp? Or is there a way we could possibly get the trophies to go into normal bag space if build bags are full? The rage and sadness I felt looking at the unlootable trophy at my feet was overwhelming.

(Okay, I'm dramatic, but seriously, how am I supposed to get my serial killer basement looking nice and cool if I keep losing the trophies?)