[GAMEPLAY] Zhonya + destroyed Nexus = vulnerable

I ulted as Karthus right before the nexus was destroyed, at the same time (an enemy champion I don't remember, let's say Kat) Kat activated zhonya. When the nexus animation was playing, Zhonya wore off before the Karthus ult finished channeling, which ended up killing Katarina DURING THE NEXUS DESTRUCTION ANIMATION. Also it announced it and recorded the kill, I checked. Today I encountered the same bug, I sctivated zhonya as Mordekaiser right before the nexus was destroyed. When the animation played and my zhonya wore off, the golden invulnerable border around my hp wasn't there when everyone else had it.

Steps:

1. Activate zhonya right before a nexus is destroyed
2. (Optional to get the kill) activate a DoT/channeling ability, ex. Viktor's ult, Nunu's ult, Kathus ult, etc.
3. After zhonya runs out during the nexus destruction animation, the golden invulnerable border will be gone, amd the character can be killed during the animation.

I think it can happen every single time zhonya runs off during ending animation, not a chance encounter.