Camille Q bug - uncastable

At some point near the end of the game, my friend died with GA on Camille. When he respawned, his Q is unable to be cast; it's not a keyboard or binding issue, as the entire skill is dark (as when skills are uncastable due to cc I think), but other skills are castable as normal. The skill also read as a mana cost of 0 compared with the standard 25. Interesting bug, but literally game changing as Camille without Q has zero damage. Worth a look into. Match history in link.

http://matchhistory.oce.leagueoflegends.com/en/#match-details/OC1/169035394/200188452?tab=overview