6.9 Kill steal bug?

I played jungle as Shyvana and when I went to gank bot, I focused ezreal while the adc and support on my team focused cassiopeia. The two of them stunned and killed her, but I got the kill? I hadn't gotten close enough to her with burnout, and I didn't even attack her. I wasn't even near her and for some reason, this keeps on happening. Anybody else experiencing something similar?