Zed swapping shadows after Malz ult

I am 90% sure there is not a bug in the video. Malzahar's ultimate has a short period at the start before the suppression sets in. I know because I play Malzahar and enemies will commonly cancel my ult 1vs1 by CC'ing me after the ultimate begins. I'm not talking about when they have a projectile already in motion before the ult begins. There is about a 0.25 second window where the enemy can just flash away or freely cancel his ult channeling. It's annoying, but whatever. You just have to learn to only ult if the enemy is silenced first and if they don't have a QSS.

Personally, it looks like Zed shot out the shadow and buffered switching to it immediately (pretty common Zed move). The game probably saw the switch as valid through the ult because of the buffer. Best I can guess.