I've crashed three times in summoners rift while playing Azir. The first time was when I went bot lane and 1v2 their ezreal and veigar. The game froze after I spammed all my moves (ulti, w>q,e,ignite). Similarily, the second time I froze was also in an intense fight. I fought 1v1 against the enemy Azir, and won. Then their khazix jumped me. I again, clicked all my abilities and flash in quick session, and the game bug splatted. The last time I crashed was when I was dead(random dc?). The enemy teemo, ezreal and our J4 and kog also d/c at some point in the game, so I assume isn't not only me.
While on the topic of bugs, sometimes when I farm minions, I can't see their health drop. But they do die when their hp bar is suppose to be 0.