IMO, most sensible people seem to have realized that this was a drowning, but there's no money, fame or political currency to be made from a simple drowning. Stirring up dim masses of protesters and spreading vague gibberish/rumors/conjecture goes a lot further for some.
There are large numbers of Black people that look at all of the self-created misery (crime, illegitimacy, illiteracy, AIDS, dropouts, etc.etc.freaking etc.) in their community with dismay. When the opportunity presents itself, whether real or imagined, they love pointing at Whites while screaming, "It's their fault. Them. Not us. They did it! They're the ones."
I believe that this is one of those instances. I doubt that most of them know the names of any of the Black kids killed by stray bullets or murdered day in day out in the hood.
They've managed to memorize a laundry list of names going back almost 3/4 of a century while largely ignoring the much more timely and relevant (and possibly preventable) deaths murders every single day in their community.
Someone once said that young people today have "Selma Envy" in which they want to be part of something important and great. They want to hold the moral high ground while working for a just change.
This isn't that.
I think that most of this is either some form of grifting or just those that are desperate to scream "White people" while ignoring the community ills that they're uninterested in addressing.
BTW,
When someone asks how a person could drown in a public place possibly surrounded by others...