[BUG] Miss Fortune kills a pink ward with only 2 shots

Spectating a game, I replayed the incident over several times to verify it.

MF had no items or buffs active that might apply any sort of burn effect.

1. I watched her shoot a full-health pink ward once, apply her buff to it.
2. She then shot it again.
3. A moment later the remaining 3 ticks of health disappeared and the ward vanished, while a nearby Annie's AA was still en route to it.