Staged and poorly, but massive props to Dubois for previously beating Usyk with a legit body shot, not sure if he could beat him again or if anyone can at heavyweight, but he won that fight.
I believe it could've been ruled either way. The ref makes a judgement call and doesn't have the benefit of instant replay.
The fact is the ref ruled the way he did and Usyk took advantage of it.
If the ref had started counting, Usyk would've gotten up, survived the round and finished Dubois a few rounds later anyway.
It was the only solid punch he landed the entire fight. 1 second out of 8 or 9 rounds... can't remember what round it actually ended. Usyk won every other moment of that fight and beat him into submission.
The correct man was still the champion after the fight.