The point is it's not clear, as there are no points of reference to use, other than his elbow, and you're allowed to punch near the elbow, as the area of the elbow isn't considered "low".
I'm not saying it definitely is legal, as the reference of what is considered "illegal" is vague, would change slightly by person to person, and the reference point is not visible in that exact situation. All I'm going off is elbow position, as that is the only visible thing to base an educated guess on. Trying to guess where a vague line is under some guys shorts is going to be nowhere near as accurate. It's like trying to guess an offside when the players are hidden.
Another thing which is clear is his belt is high, like 95% of boxers have their belts too high. The only reason they have high belts is to prevent themselves being hit or to deter legal body shots. this is why I have no real sympathy for Dubois, as his belt was just as high, so he may have been done over by rule bending, but he's maybe being done over by the same way he's bending the rules.
If he was going to use body shot tactics then maybe he should have had his belt lower, and he could have used himself as a reference point for the ref, when he got the inevitable complaints.
I'm not fussed who says it is or isn't, unless they've got some way of proving it, which I've not seen yet.
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