1. Not believing that the duct tape covered the mouth. With all the talk of animals and water degrading things and moving bones around, and the fact that I do believe Roy Kronk (not maliciously) interacted the bones, I consider it a reasonable doubt that there was some other explanation. One reasonable possibility I would consider is that whoever disposed of the body was trying to prevent fluids from leaking, or bugs from crawling into the mouth AFTER the child was dead.
2. At least some of the testimony from GA and CA was put into doubt. CA provably lied about the searches at that time of day. She was at work. GA I believe lied about the extent of his involvement with River Cruz. At the very least, he was pretty darn combative on the stand.
3. I found JB's argument that chloroform was looked up after seeing TL's graphic about it on FB was a reasonable doubt. He did apparently have an image on it on his page. The search was apparently done after this. One report said 84 hits, one said 1. The discrepancy, combined with the explanation, creates a reasonable doubt.
4. The story of burying pets did actually introduce a reasonable doubt. Someone tried to bury the child in the yard, but realized that was unreasonable, so disposed of it near the house. I think originally the body WAS buried, as well as the person (and I think it was Casey) could manage. But with all the animals and especially the water I think it would've 'bubbled up'.
An alternate reasonable scenario could be this: the child drowned. Casey, who obviously has poor coping skills and is immature in general, freaked out. She fell back to lying, because she was scared. She was in denial and freaked out and partied to try to forget it -- some people turn to drugs to drown things out, some to alcohol, she turned to partying. The body was in the car, and started to smell. She gave it the best burial she could in the swamp. Things DID spiral out of control for her. She had poor coping skills and just dealt with it totally and utterly wrong, Truth and Casey are just not acquainted with her. I doubt it even occurred to her to tell the truth! I don't think George told her "you will go to jail for the rest of your life" but she might have truly believed that.
Now, that said, I don't think that's what happened. I think she had a hand in the death. I just don't see how it was proved, because there's what I consider to be a reasonable alternative scenario above. Do I believe it? No, not really, but I'll allow it could have happened like that. She is immature enough, a pathological liar enough, sociopathic enough, and just plain batshit crazy enough to make me believe she could do utterly unbelievable things.
If I was on that jury, I would be dying to charge her with improperly disposing a body. Because I think the body was in the car. And though I think she probably had a hand in why there was a body, I think it's possible she didn't, under a reasonable (and not just out-and-out crazy) scenario.