During the talk Jessie has with her father in her room, they're shown sitting on the right side of the bed. After Jessie's father leaves the room, she collapses onto it. However, the next shot shows her lying down with her feet dangling from the left side of the bed.
It is very unlikely that the car's airbags wouldn't deploy with such a hard crash.
When Jessie gets into the car, due to her weakened state, she forgets to put on her seat-belt. Hitting the tree at that speed, she would almost certainly have been thrown through the glass and not survived.
Gerald explains that the meat Jessie wanted to feed the dog is "Kobe rib eye" and "$200 per portion" but the package said it was a tenderloin (so a different cut of meat completely) and $199 per pound. One pound wagyu steak seems like a big portion.
When Tom is talking to a young Jessie on the shore of the lake, the sun is at 12 o'clock directly behind his back. However, the shadows place the sun at 9 o'clock on his left.
Even though there for days, there were no references of needing the toilet.
Before Jessie breaks the water glass, there is still some water left in it. If she's so dehydrated, she would have drank the water, rather than tossing it out.
There would have been quite a few ways for her to escape. She had days of time. For example, he could have stood up, then stomp the bed away from the wall with one leg, get behind the bed and move it closer to the phone or the keys. Furthermore, in that position, she would have had plenty of time to rattle the bed until it would have come apart.