x 2 random creeps show up in lane (not in a wave)

Hi, so... I was recording a 10 min video for my youtube as a "last hitting" visual guide in calculating total xp / gold and level up by 10 min. Basically using practice tool, and throwing 6 infinity edges on, using enemy dummy at my base to keep my lane minions at base and a friendly dummy to keep enemy minions at the lane and not into tower and sat in lane and just let my champ execute each minion wave.

I tried to record twice, since the first time I recorded... 2 separate times x2 random creeps showed up in lane.... They could not have been from other lanes since I had turrets invulnerability on and the other two lanes were basically resetting each wave.

So, I tried to record again thinking wtf... and sure enough by nearing 10 min a random set of 2 minions appeared between a wave. I will post the video so it can be seen.

I am curious now to know if this is happening in normals or ranked or if it is isolated to the practice tool. 4 additional cs in 10 min is a big deal, even 2 can be a big deal when it comes to chasing that power spike. It felt as though the game was stacked in favor of Blue seeing those additional minions appearing... What is this Rito?

[slayer-jinx-unamused]