Close. Actually the parabola part didn't play a part. What actually occurred is that, when you're dashing to another unit (for reasons I cannot fathom) you arrive at a random short distance from them. If you started your dash at a closer distance than that random short distance, but not exactly on top of them, some funny math happens.
In order to smooth the arrival (again, for reasons that I cannot fathom), the two distances are divided by each other to come up with a speed scaling factor. Unfortunately, that can lead to dividing a larger number by a smaller number. Sometimes a much smaller number. So for a single frame of simulation, Lee (or Irelia, Jax, Yuumi, etc.) could report that they're going hyperspeed. Like cross Summoner's Rift in a tenth of a second fast.
Then, in the area trigger/missile collision, we ask "hey, where were you last frame" so we can do "capsule collision" (pretty standard game collision technique). In order to compute that, Lee says, "Well...