I suddenly could not cast any spells?

Suddenly in a ranked game, I could not cast any spells. I turned off quick cast, turned on again, still nothing. Normal casting? Nope doesn't work either. Closed client fully, then start it up again as admin? Nope didn't work. Hmm.. Maybe it was my computer? Thank goodness my roommate is part of the PC Master Race with a Corsair K95 Lux Keyboard. Logged onto his computer to play the game. Nope couldn't use any spells (as you can see in the video) couldn't even go back. I tryed manually clicking on the spell and casting, doesn't work. Maybe try running as admin on his computer? Nope, didn't work either. Oh wait! My roommate also has the brand new Macbook Pro, how about we try that? Nope, didn't work either. Riot has effectively wasted my time. Logging in now after my game has been lost, I can now use my spells. This is awful. I don't want to risk playing another game just to find out this will happen again suddenly in a game. I lost 17 LP and would have actually won that game if my spells didn't start messing up. Truly, I really do mean I would have won the game since I was 7-1 as Pantheon and was 4 dragons ahead and a few turrets ahead and was gonna go get Baron with my team. Absolutely disgusting that my lost wasn't even forgiven.

Edit 2/28 3:38 PM: Is it safe to play League? I'm not sure, I want to see what Riot will due to rectify this situation. And I feel bad for my teammates who lost the game too because of me. They tried to help me in chat and give me recommendations but to no avail.