If you WHOLLY accept his version of events you have to believe contradictory things.
Toni is TERRIFIED of Rab but is risking having an affair and deleting ALL media relating to it to keep Rab from finding out.
Toni likes the accused so much she is risking an affair (despite her violent boyfriend) but also hates him so much she wants the world to think he's a child rapist and murderer.
Toni is scared of Rab and confided in the accused over a period of months BUT when it came to framing someone she opted for the accused and not the boyfriend she's been complaining about all that time.
And also that she is some form of superbeing that doesn't appear on CCTV images and can get his clothes from the beach, get Alesha out the house with her kit of assault and semen transfer implements, carry kit and child to the crime scene, commit the crime, then get his clothes back to the beach, permanently lose or destroy her own kit and clothing, wash her body, and get back into bed beside Rab without anyone noticing her absence and without transferring any of her own DNA to ANYTHING, all in about 28 minutes.
If I were a teenager, having a friends with benefits connection with another teenager, behind my older boyfriend's back, I think I would also delete all media connection to stop him from finding out.
She's young. She's decided she doesn't like the teen any more - why not point the finger at him, gets him out of her life. Plus,she is still living with her older boyfriend despite her - alleged - complaints about him, so he can't be that bad.
The only cctv that we have heard about was on the shore road. Therefore, take a different route, no cctv.
Clothing - she could have got hold of his clothing in advance. No need to get it out of the water.
Take Alesha out of the house, very easy for her.
Carry child to scene. Harder for her to do.
Put clothes into water afterwards. Easy for her to do, though you would have to question why she would bother, if she is trying to frame him.
Destory her own clothing. Easy to do.
Get back to bed without having been missed. I can say, from personal experience, this is very easy to do.
All in 28 minutes ? where did that timing come from ?
Am only posting the above to show that I could find an answer to most of your reasoning. Not saying for one minute that I believe anyone other than the accused carried out this crime.