[Gameplay] Unable to complete tutorial

I tried to introduce two friends to League yesterday, and both did not get a good impression of the game. The following bug occurred on two separate PC's, with two separate newly-created accounts, both with the current patch as of 1/3/15.

During the tutorial, after Ashe fights two minions, Ashe will level up and be prompted to select her "W" ability. After selecting, the 4 minions she is supposed to kill never spawn in. It is possibly worth noting that both players who this occurred for did move forwards slightly to a position just in front of their side's turret before selecting the "W" skill. Thinking they had possibly missed the minions, we attempted to backtrack but could not find them spawned in anywhere, nor could they suicide to the turret, which would not deal damage to kill them.

Both had to Alt-F4 to close the tutorial. One of them tried it again and got the same result. Attention to this would be appreciated, as it left them with a negative impression of the game, and I doubt I'll be able to get either to give it another shot.