Riot: You have to ban Ezreal by your own rules.

10.1.1.4 Exploiting. Exploiting is defined as intentionally using any ingame bug to seek an advantage. Exploiting includes, but is not limited to, acts such as: glitches in buying items, glitches in neutral minion interactions, glitches in Champion ability performance, or any other game function that, in the sole determination of LCS officials, is not functioning as intended.

You're own rules state that playing smite ezreal mid with runeglaive is cheating. So either you punish the teams that played it (which would be a horrible idea), or you just ban it like Shen when he was bugged. There's precedent here, and it's really lame to watch you let teams get away with cheating. You can't ignore your own rule set...