Kalista's passive glitched [GAMEPLAY]

I'm playing in my game and I look bot when a teamfight breaks out. Noticing Janna's low, I Ult and Kalista on the enemy team, Ult's to negate my ultimate. Nothing big here. But later in that game, my team noticed that still had her passive , , in her inventory. My team was amazed, because she had ulted in the bot lane teamfight. I don't know the reproduction rate, or is a glitch that just happened that game.