The case law you've posted is for a burglary, there first point of proof for a burg is to enter a premises or part of a premises as a trespasser. Our original poster has not entered as a trespasser.
To answer your question how I came up with the idea the security could be trespassers, I'll explain
Lets call the person posting this question the victim as they are making the initial complaint.
Lets also use the known facts he has provided as we have no account from the security guards.
Lets also assume, there are no cameras in the disabled toilet.
The victim has entered the disabled toilets, he has a lawful right (unless previously banned from the shopping complex) to use them as they are in a public place.
Once he is in there he has a lawful right to use them and he is now as the law stipulates it, in a "private place", a place where one out reasonably expect privacy, and he is now the lawful occupier of this private place.
The points of proof for trespass are:
- wilfully enter a private or Scheduled public place without express or implied authority from the owner or occupier;
The security guards have entered a private place, without the express or implied consent of the occupier.
In this instance, the victim is in a private place, and is the occupier, and clearly has not given expressed consent to enter (implied consent does not exist if the door was locked)
HOWEVER, The security guards would have likely had a genuine reason for entering. I can only guess, that our person posting this may be known to them and he is a frequent flyer who uses the charger in there regularly and has been told not to, hence their reason for entering.
I'm only guessing and this part would be for the police to find out by asking them what happened.
Now lets reverse this and look at our original poster from the security guards point of view and lets now call him the "offender".
What offences has our offender possibly committed?
The toilets are in a public place so he has a right to enter them.
He has not committed a burglary, because one must first enter a premises as a trespasser with the pre-formed intent to steal, damage or harm.
He may have well and truly formed the intent to steal electricity before entering the toilet, so not a burglary but perhaps a simple theft of electricity.
In saying that, if a power point is publicly available, a reasonable person may believe they have the right to use it, and this would eliminate any mens rea from the offence.
So in summary, I dare say our security guards were investigating a theft of electricity, under what grounds I dont know, because how would they know he was using the charger? By seeing him on a camera taking his scooter in there? Previous interaction? Who knows.
Our security guards would need to have some well established reasonable grounds for entering the toilets, and i'm sure they did have.
Because if they didn't they would have a serious civil litigation fight on their hands