[GAMEPLAY] Corki's map position reveals randomly after 30 mins

I just finished a game as singed playing against a corki. After killing him once around the 30 minute mark his character would reveal on the map at random intervals where we had no vision. Additionally, even when across the map with his character unselected and through fog of war I could hear his sound effects at full volume including the effects he makes when walking like "flyin' high"

I don't know how reproducible the bug is but it seems a kill on corki as singed after the 30 minute mark does it.