Only, I suppose it's possible it wasn't as random as losing a mattress off a truck, going back to pick it up, and then finding a phone. I think the narrative may change when it's reported what this random does for work.
And more, the area where the phone was easily found was an area Jelani's mom requested to be searched, and apparently never was, according to the previously posted interview.
So again, I suppose if you fall into the suicide camp, this is just another instance of Jelani disposing of his belongings before putting himself in the water. But, if you're leaning towards homicide, then this is someone concealing a crime.
DNA tests from the car, any highway video footage they've pulled, and phone records should bring some clarity to both camps. In the meantime, we're still just speculating and watching a mother work relentlessly (under some judgement) to find out what happened to her son. I suppose she gets the same freedom to speculate until there are more facts released.