I've seen two documentaries, and also a drama about the case. Very, very odd.
Regarding the pineapple, I think it was suggested that Burke had some in a bowl with milk after arriving home from visiting friends. Jonbenet was in bed by this time but got up and, seeing Burke with the pineapple, nicked some out of the bowl with her fingers. Pineapple was found in her system at the autopsy, even though she hadn't had a meal containing it.
It was suggested that Burke lost his temper, picked up a torch and hit her on the head, causing a fracture. She fell unconscious, but the blow did not kill her. The fracture shape matched the torch, which had been wiped clean of fingerprints. The batteries had no fingerprints either.
In order to make the incident look like murder, Jonbenet was then garrotted with a garotte comprising string and some wood. They must have assumed JB was dead from the head injury.
.
Patsy then rang the police but didn't hang up properly. Voices were heard in the background by the Operator. There were more Tha two voices. Patsy composed the note to make the incident look like a kidnapping.
So much is odd. The Ramsays tried to flee Boulder; they did not co-operate with police; Patsy was wearing the same clothes as she had the previous day etc.
I think Burke did it and the Ramsays tried to cover him. I saw him being interviewed and when the interviewer said "did you do it"? , he replied "what evidence is there"? I'd have expected him to say "no", I did not do it.".
Must look at Reddit.