When Lori and Declan are looking at footage from the dance, they see Lori and Hillary dancing, and Jessi is standing behind them holding Lori's necklace. When the dance happened, the electricity had gone out, which ended the dance, and Jessi had gone home. When Lori took the garbage out, that's when Jessi beat her up and took the necklace, then disappeared. Lori landed on the ground unconscious with a huge bruise on her face. Even if the dance had somehow continued after that, Lori would have cuts and bruises on her face and neck, and Jessi wouldn't even be there.
Kyle professes that the odds of both he and Jessi being selected in the raffle to compete in the "hands on a hybrid" contest as being 20 out of 4,000 (represented in decimal form as 0.005) because there are 4,000 entries and 20 people selected, but this is a wildly inaccurate calculation. Considering that the number of ways that 20 contestants can be selected out of a pool of 4,000 is a 54-digit number, and there are 7,998,000 in which 2 specific names (i.e. Kyle and Jessi) can be selected, the probability of them both being selected is far far less than 0.005.