[GAMEPLAY] Mouse and keyboard stop working properly

First off, I have not yet been able to determine what (if anything) directly causes this bug. It seems to happen randomly and is usually connected with either death or recall, since I can't remember it ever INITIATING outside of the fountain. It happens maybe one game in fifteen or so, and has been going on for at least two months now.

What happens is this: I suddenly find myself unable to right click. Instead, my left click has morphed into the Attack-Move command (no other method of movement works), and each of my abilities is triggered automatically at my cursor as soon as I press QWER. I cannot press Escape to get to the controls to try and fix it. Every time I force quit to reconnect, it resets itself and works fine. However, my internet is slow and while my gameplay almost always runs smoothly, having to jump out of a game for several long minutes to fix this bug tends to make those games much harder to win. I have been lucky that it has yet to happen in ranked.

I'm on a MacBook Pro (OS 10.10.1) Mid 2010, 2.4 GHz Intel Core 2 Duo processor. If you have any other questions about my specs, please let me know. I'd submit game logs, but I have no idea how.

I'm holding out hope that there's some kind of obscure key binding that's causing this and I merely need to press it again to fix it. I know that if that isn't the case, this is the kind of bug that will likely take along time to isolate, let alone fix.

Thanks!