I agree, I think these accidents are common and it's plausible in this case.
However, this one, I am becoming more and more skeptical of the more I look at it. Honestly, I think that SUV being in the same spot is maybe the largest red flag I see. The fact that it was so quickly deemed as unrelated was not giving me a feeling they were interested in investigating anything at all.
For instance, since we know this car was a stolen vehicle. If the windows were broken or there was a way for a body to float out of that vehicle, who's to say that we couldn't define this location as a dumping location for bodies/cars?
So there might not be a direct link to this particular case, but if that vehicle was dumped there, then why doesn't it make sense logically that the same person might use the same location to make another car disappear?
To me, it's the same concept as if you found a body in a field and then you found another body... You'd logically suspect that they were buried by the same person. So two different missing person/murder cases, but the same murderer.
It's confusing to me how in what seemed like an hour or two after that vehicle was found, it was deemed unrelated. Strange imo.
I definitely see the possibility of an accident here in this case, but if that SUV wasn't there, I'd be more likely to exclude foul play. I think someone should be looking for a body that has possibly been found along the missouri river in the last year. Just to be thorough. there might be some way to connect that vehicle to such a body. In turn, that body might have a connection to a person in this case.