Fiddlestick Ult channel bug

I found this bug when I was playing a game of aram. I was playing Caitlyn against a fiddlesticks. And I put a random trap down at the end of a bush near a fight my team was in and when it put it down I got lucky and saw fiddle was channeling exactly where I put my trap. And after the time it takes for caits trap to actually set to snare I heard it go off and I saw fiddle stick, since the traps give vision of someone that triggers them, then all of a sudden fiddlesticks ult completes and he tps the short distance with his ult going. And I know fiddlesticks ult can be interrupted during the channeling because ive done it before. So basically even though fiddle got snared during his channeling with a cait trap his ult still finished.