Dying While in Zhonya's Hourglass

Hello, the most recent game I played was as Karma. During a not so great team fight Katarina used her ultimate, so like anyone would probably do I used Zhonya's hourglass. It made the sound that it usually does and went off perfectly and I was golden and invulnerable . However, right as I activated I died. I'm almost 95% sure I was in hourglass form. Unfortunately I do not have video of this or a screen shot of this event. Now, I don't know if this is a one time thing, or if it has happened before. I know there has been issues with Zhonya's hourglass in the passed, not specifically for this particular issue, but issues in general. If anybody else experiences similar problems feel free to comment or post.

Thanks, Swallower