New Summoners Rift in Team Builder Minion Block

I didn't manage to get footage/images from my most recent game but the minions all spawned regularly, and the ones headed for top lane went to top lane. They walked all the way to the outer tower(which had not been taken yet, so it was still up), and the proceeded to walk upwards a bit and just jam onto the back end of the turret. About three or four of them stood on the backside of the turret, no walking animation. It was late in the game, maybe 35-40 minutes. Not sure if I could recreate or if pure chance. I'll be experimenting in top lane a bit to try to get it to happen. It wasn't siege minions or anything big, it was either melee or caster minions; I believe caster minions.