Wow, most people have covered everything that needed to be said, so I guess I'm only agreeing with them
No one should de-value your BB, you worked hard to earn it. That being said, you are a yellow belt, and Hugo is your senior, so it is wrong for you to offer advice to a senior rank. To put this in perspective, we practice
martial arts, referring to military. You would never, I hope, tell a higher ranking officer that they are undeserving of a promotion. Things like that are disrespectful and come with heavy consequences (even if your opinion is the right one!).
Everyone has their place, and people need to know what theirs is.
I don't believe age is necessarily a factor, I have been practicing MA since I was 5, and because of MA I have always been the mature one for my age. This is because of the tenants of martial arts that I strive to live my life by.
At the same point, I don't believe Hugo should be kicked out of the dojo. He has made mistakes, but that doesn't necessarily make him a lost cause. There are times that the "cancer" needs to be surgically removed before it metastizes.. . But it doesn't sound like he is a cancer to the dojo YET.
MA can be an avenue to better his character when proper influenced and fostered.
Although, it may sound underhanded.. . Sparring him as a junior rank and humiliating him (not hurting him, there is a difference) is a great way of putting things in perspective sometimes. But it's a mute point now, since you've already spoken and made amends.
A BB, doesn't just mean you are skilled. It means you have internalized the ideals and concepts of the art. OBVIOUSLY Hugo has not done that yet, these things only come with time. You can lead a horse to water, but until he's thirsty he's not gonna drink.. .