Champion Unable To Move Anywhere But Straight Down Mid Lane

I just finished a game of SR, not too long before posting this. I was in TeamBuilder (if that makes any difference later on) and chose Teemo Top Lane. I had all my stuff set up and ready to go. I found a team and then we found a game.

The loading screen took almost forever, even though everyone was at 100%. [From my point of view, at least.]

However, the issue started once we finally got in game. I loaded in, bought my starter items and then clicked the mini-map where my outer-most top lane turret was, so that I could head to lane. This wasn't what happened, though.

Instead, my champion (Teemo) began moving straight down mid lane, instead. Like, literally, STRAIGHT down the lane. I tried everything I could do to stop him from moving there. I clicked bot tower, nothing. I clicked where our Red Buff is, nothing. I even zoomed back to base and clicked that like 20 times, still nothing. As you would assume, I was executed by mid tower.

My team called me a troll and thought I was doing it on purpose, even after I explained my situation. (Why wouldn't they? I honestly can't say I wouldn't think so, if I were them in the situation.) So, I respawned and tried again. Nope. Still got sent straight down mid, while also giving first blood to the mid laner and being called an intentional feeder. (That makes me feel a whole lot better about the situation. end /sarcasm)

Anyhow, I dc'd then reconnected, soon after. I was able to move freely after doing this, but, at that point, their top laner (Darius) was already level 4, while I was still level 1. Needless to say, he took full advantage. I had confidence in that game, going in. But, with this bug, (along with the Darius's "I'm better than this Teemo player, despite taking his situation into account" comments), I wound up tilting horribly.

I would really like to know what this bug and/or glitch is. As well as, the best way to stop (prevent) it from happening again.