Syndra's Ult + Shaco's Ult = Syndra's Ult Is Refreshed (VIDEO)

If Syndra ults a Shaco while he clones himself with his ult, Syndra's ult cooldown seems to be refreshed. In the video, then enemy ults my (Shaco) then 6s later ults my ally J4. You can later see the death recap, confirming I've been hit by Syndra's ult. Only encountered this bug once.

To reproduce: -Pick Syndra and Shaco on different teams. -Syndra ults Shaco while he's cloning himself with his own ult

Idea: You know when spells gets half-cast because you instantly die or lose vision (part of the VFXs and SFXs are there but the spell neither completes itself nor goes on cooldown)? I don't know if it's the same phenomena but I thought I might related.