Unsealed Spellbook gamebreakingly bugged?

Alright, maybe the title is a bit missleading. It is no "pick it and win 100%" bug. I played a game of with it. I used the second swap of the game to exchange to . The timer on was already a lot longer then the timer on which I got from my first swap and when the timer run out I remained with exhaust as my active Summoner Spell until I used it and I was unable to swap again before using it.