Yet again pure surmising no substance.
Well there are 17 things the evidence shows Sheila did or people suggest she did.
All these were done between Nevill terminating his last phone call & the police arriving.
Obviously impossible to do all of these in 14, 24 or 40 minutes. Even if Sheila worked like a navy seal straight after Nevill put the phone down.
Now if Bamber had said he received Nevill's call at 2.20am......the problem here is there is now over an hour before he phones the police.