Galio ult bugs

So I recently played a game of Galio and I found a few issues with his taunt. At one point I ulted the enemy rammus and mid way through my ult he taunted my katarina. Not sure how he was able to do this. But this effectively stopped my katarinas ultimate.

Later in that game the enemy Malzahar ulted my ally Katarina so I ulted the enemy Malzahar. Katarina being low on health ran off and somehow Malzahar followed. The taunt symbol stayed above Malzahars head as he walked out of my ult and walked towards Katarina. After this we asked him if he could use spells and he stated he was unable while my ult was active.