The following happened:
In my turn, a soldier fires a burst of three shots from his Laser Rifle, killing one alien and stunning another one. After this, another soldier shots twice with a timed shot from the Grenade Launcher, but both grenades bounce and drop down into the void. After the second shot the formerly stunned alien all of a sudden dies.

> 2013/05/27 10:28:57 Team 1's round started!
> 2013/05/27 10:29:30 [STATS] ShipIt (Kyoumi van Grieken) kills alien (Wzszh Vzs Wzshf) with Pulsed Fire of laser_ammo (entnum: 44)
> 2013/05/27 10:29:30 [STATS] ShipIt (Kyoumi van Grieken) stuns alien (Zmuknesk Zr Znaztrk) with Pulsed Fire of laser_ammo (entnum: 40)
> 2013/05/27 10:30:01 [STATS] ShipIt (Jassir Al Hashimi) kills alien (Fhzwh Vze Hzwzf) with Pulsed Fire of laser_ammo (entnum: 43)
> 2013/05/27 10:31:25 G_ActorDieOrStun: State wasn't changed
> 2013/05/27 10:31:41 [STATS] ShipIt (Xavier Baldwin) kills alien (Zmuknesk Zr Znaztrk) with Snap Shot (Timer) of grenl_plasma_ammo (entnum: 40)

I remember there is a report about smoke grenades, where essentially the same thing happens (grenade falls into the void, smoke appears somewhere on map).