Seriously, who cares that he was possibly hacked. The simple fact the video even existed is scummy.
And saving a video like this to a social media account is idiotic.
Just so you understand... when videos like this (or the hundreds of naked pictures of actresses like Jennifer Lawrence) leak out onto the internet... it isn't because the athlete/actress posted it on Facebook or shared it privately on instagram. Usually, there's some kind of exploit on their device (or the device of the guy they are snap chatting pics to) that allows someone to take the content. If we're going to accept the narrative that D'Angelo didn't send this off to the "FAMEOLOUS.com" website himself and it was actually stolen, then there's really no telling exactly how that leaked out. In many instances during that "fappening" scandal, people had their iCloud photo backup automatically turned on and weren't at all aware of it. So every photo they took was being backed up online and remained there even after they deleted them from their device. In other instances, people had their iTunes account compromised and people were able to just log into the "Messages" app from their computer... and see all photos/videos/text messages in real-time. For instance, I'm able to access my text messages from my iMac via the "messages" app... and there's been instances where I've deleted entire conversation threads (because my freakin iphone is always out of storage), and see the entire message thread (including all photos and videos) remain visible on my iMac. That's concerning, because it means anyone who can figure out my iTunes login/password can sit and watch as I have private conversations with friends and family.
Another possible way is an exploit on an app like snapchat itself. Recently, thousands of private photos/videos from countless individuals leaked out onto the internet. A massive archive of them were being shared on torrent sites. It was messed up. Even more messed up when you realize that a lot of the people in the photos were under 18 (teenagers snapchatting each other). I haven't researched that one too closely so I'm not exactly sure how that breach happened, but the point is there's numerous ways that video could have gone out.
In the case of D'Angelo Russell... where it's actually been proven his instagram account was compromised 10 days ago, it could be as simple as his password being something stupid like "dmoney1"... or someone obtaining it via a phishing e-mail... Another really easy way is to answer "Lost password" questions. These guys are public figures. If the questions are something like, "When/where were you born" or "what's your mother's maiden name", it wouldn't be at all hard to find that information for a celebrity. If these "hackers" can gain access to his e-mail account, they can very easily gain access to the majority of his other passwords (facebook, instagram, twitter, itunes, etc), because they can just go to those sites, claim their password "lost", and have a password reset sent to the e-mail account.
HOnestly, when they present this as some "hacker" gaining access to his device it makes it sound more outlandish than it really is. Usually these aren't some brilliant genius coders sitting up to the wee hours of the night finding there way past digital firewalls. Usually it's just some 14 year old pervert trying to find Kendall Jenner nudes and answering "lost password" questions that are way too easy to answer. Then when they gain access to someone's e-mail account, they can gain access to everything. My crazy Aunt literally got into my mother's facebook account using this exact method and the both of them are basically computer illiterate.
So yes, I think it's pretty plausible that this video leaked out unintentionally. Maybe Russell just took the video (in response to Nick Young taking photos of Russell with playboy models), shared it out with their network of friends (or perhaps even just directly to Nick Young himself), and the video got acquired by someone who wanted to embarrass Iggy Azalea.