Gothik shadow bolts cast time and targeting - is it bugged?

So my guild did Gothik yesterday. We got absolutely destroyed by shadowbolts after the boss spawned. He would sometimes cast several shadowbolts within a second, and he would cast on seemingly random targets.

https://sod.warcraftlogs.com/reports/pXQMFLm8KtHRdjNf?fight=last&type=damage-done&view=events&hostility=1&source=208

Compare that to these two kills from yesterday by other guilds, one on heroic and one on mythic: Boss only targets the tank and mostly casts shadow bolt once every like 1,5 second.

https://sod.warcraftlogs.com/reports/jhmWY24DNwvB6Pky?fight=46&type=damage-done&hostility=1&source=208&view=events

https://sod.warcraftlogs.com/reports/9bYKWh1dPAwR7a3c?fight=41&hostility=1&source=182&type=damage-done&view=events

Am i missing something?