@HappyHourSumwur Ran into a lifeline doing this on the opposite team during a Control match. I was happy at first because I was like "I sneaked up behind her and one clipped her!" Then I noticed the same LL behaving weirdly, i.e., just standing still, moving to out-of-the-way corners of buildings, wandering aimlessly around the enemy spawn (I love to harass the enemy spawn on Control) and I figured she was just a bot. So, my self-confidence dropped.
Interestingly, there was always a certain member of our team (with a TTV in the name) nearby when I melted the LL, and he dropped the match soon after, so my tinfoil hat wonders if he was somehow dual-queueing for easy kills. But, what are the chances he would get matched against the LL bot? Doesn't seem likely.