Game not ending after nexus is destroyed when inhib respawns just after

As you can see in the screenshot, it was a bot game. There was no health bar on the enemy nexus. It seems one of the inhibs respawned just as the nexus was killed. When we killed the inhib we could kill the nexus again.

Because the bots said their thing I'm convinced I didnt just 'think' the nexus was down... (see screenshot)