Teemo Passive Bug

I was spectating a game today and up in the top lane bushes i saw something weird. The Teemo was stealthed in one of the larger bushes but the Fizz knew he was there. Teemo went into stleath on the right edge of the bush but then moved to the left edge. Fizz threw out his ult horizontally across the bush but chum in the waters stopped at the spot Teemo entered stealth on. It should have continued traveling through the bush and (probably) hit teemo on the left side, but instead it latched on to where teemo entered stealth on the right side. I haven't tried recreating it and since its a weird interaction it probably doesn't happen much. But a dead teemo got anyway and I can't let that go.