For misadventure Libby has to start outside the park in Oak Road.
People can't speculate on her being left close to the river by PR because that hasn't been his defence.
In none of his stories does he take her into the park. So no 'left close to the river' option should be considered really. It is not been presented for some reason. Which is, in itself, suspicious.
Earlier CCTV shows she can barely walk and has often been helped up. The darts players found her lying in snow.
By this point she'd be colder and her blood alcohol is still 3 times the legal drink limit as per the toxicology reports. The terrain is less conducive to walking. She avoids all CCTV.
How do the misadventure theorists get her to the river avoiding CCTV from outside the park?
Who was the man?