It's confusing that Tangmo would need to use the bathroom if they were near land since she swallowed a lot of sand/mud. This is probably why she was found closer to a port. If they were near land, they could've stopped for Tangmo to use the bathroom. There's no way she would've told them she needs to pee in the water if the land is just a couple of minutes away. They must've lied that they were farther away to hide evidence.
If I was tangmo's loved ones, i'll be so pissed at everyone involved + the police. They're doing such a crappy job. Why is it that the netizens are the ones that have to literally solve the problem or find clues for them to figure out the case. At this point, they should just quit if they're going to do a poor job at their job. It doesn't help that they must've been bribed too. Too corrupted. Very saddening that there's so much chaos around Tangmo's death and case. If only she had survived. I'm hoping Tangmo gets the justice deserved if this was foul play and not an accident. I wouldn't want those at fault to get away but punished instead, because who knows what they can do to other people in the future too. If they can do something bad like this, they can and will do it again to someone else.