I really wish the "murder" had been more explicit. I think we're supposed to see it as Alex flying into a roid rage and killing Bryce, but the direction gave it an ambiguity that allowed for a reasonable explanation of "oops." Which is something I don't think they were going for in this scenario. It all happens really fast. Bryce is lurching and hurling accusations at Jess and Alex pushes him into the water. I don't know that him dying was the intention, which makes the convoluted cover-up all the more problematic. Sure, he falls in the water and begs for help, but he almost immediately drops below the surface and drowns. It's not like they stood there for a long time just watching. I can easily conceive of a scenario where they were both kind of in shock and by the time they snapped out of it, it was too late. That could have been reasonably explained without jeopardizing them or anyone else.
Zach's culpability is far more problematic for me because he literally confessed to beating the guy to within an inch of his life, breaking both an arm and a leg for good measure and then leaving him there. As stated, without Alex and Jess showing up, he probably would have died anyway out there overnight with no way to seek help. And the police know this, because he told them. And then released him saying "don't worry about it kid,he drowned." Maybe he drowned because he was beaten near death and had no means to call for help. A reasonable person could assume that Bryce fell into the lake on accident while trying to drag himself towards help after being beaten. Alex's assist almost seems incidental.
This is probably the biggest reason I don't look forward to them rehashing this storytelling in the final season. Tyler did what he did, I get it, but I feel like they put a pretty bow on even his creepy picture taking. A coffee house exhibit, GREAT! Not so creepy after all, but you know, still a little creepy. A crime he tried to commit, but ultimately didn't? How interesting is that really? Dead dude blamed for a murder that has like EVERYONE's fingerprints all over it? Eh. Who is going to investigate it? The Deputy who is already aware of all of it and even helped by burning his kids clothes from the night of the ill fated swim lesson? Really?
The biggest mistake I think they made here was sort of saying rape=bad, murder=okay, if they were a rapist. Don't get me wrong, I too would have no problem with rapists "just disappearing" into a lake in the middle of the night. Fine with it actually. And if that was the narrative they were going for, I'd be all in. Dexter was one of my favorite shows, you know until it turned into trash. I don't need them in jail, just tone down the self righteous indignation. Zach was all about ratting on Tyler but took his sweet time to turn himself in. And of course no one cared anyway, because beating crap out of someone, breaking their limbs and cracking their skull is like not really a crime. It was in that moment of confession that I needed the "murder" to be more explicit. I was happy for Zach. I saw the relief in his face upon learning he hadn't murdered his "friend." I saw it and I don't think I'd convict Alex if the truth were laid bare. I'd totally think that dude who broke his limbs and cracked his skull was worse than the dude with the limp who tried to protect his ex from a raging rapist. I don't know, maybe that's just me,