[GAMEPLAY] Visual bug on Guardian Angel item cooldown

In this game, Riven's Guardian Angel is procc'd at 34:26 (she finishes reanimating at 34:29, which is when it goes on cooldown). From her rune & item setup, she has a total of 5% item CDR (from the Cosmic Insight rune and no other item-CDR effects). 300 seconds * 0.95 = 285 seconds or 4:45. So the correct time the item should come off cooldown is 39:14.

You can see in this video that the item appears to come off cooldown at ~38:45 (a cooldown of ~4:16), but she does not get the swirly effect around her character model, indicating an active GA.

The Riven dies at 39:08. She said in all-chat that it must be bugged, because she had looked at the GA in her inventory and seen that it was off cooldown.

You may also note in the same video that when the item is placed on cooldown at 34:29, it immediately has the ~44 second cooldown refunded / removed from the total cooldown (that's the bug).