Weird Kalista bug

I was playing an ARAM as Sion and we had a Kalista on our team, I think she may have been new to the champ as she didn't bond with anyone till lvl 7. Well she chose me while we were under tower and low health. As the soul bond animation was playing GP ulted us and killed us both, afterwards when Kali ulted I could not activate the ult and my character model didn't disappear as usual I would just watch sion walk around on top of kali until the ult duration wore off.