Simple explanation for the pineapple...

Even more likely the pineapple was for Burke and she grabbed some when he wasn't looking and he hit her over the head with something and it ended up killing her. The parents than freaked out and tried to cover up the accident.

At 11 years old Burke's interview when shown the photo of the glass with tea bag and the bowl of milk and pineapple. His expression was as if he was caught.

Only moments before he was acting a smart ass, saying he knew he was there to talk about Jonbenet, slumped on the chair. When the interviewer showed him the photo Burke said "Oh" and leaned forward. The interviewer asked what the photo was of, he acknowledged the glass with a tea bag (which had Patsy and Burke's finger prints on it) however he would not give a straight answer about the bowl.

He says it is a bowl with cereal or something. When it was clear it was pineapple pieces with milk. The bowl had Burke's finger prints on it too.

As Dr Werner Spitz said the pineapple was partly digested when the autopsy was performed and he was present at the autopsy.

Actually it was Dr Werner agreed with the experts on the theory that Burke was having a late night snack of tea and pineapples with milk. Jonbenet became cheeky took a piece and ran out of the room. In a fit of anger or annoyance he grabbed the flashlight and hit her on the back of the head. Killing her instantly (she was brain dead before the garot) and in a panic the parents covered it.