Potential gross misconduct?
"Gross misconduct has to be clearly defined and then proved. It cannot be retrospectively defined, but any contract can have broad scope by referring to 'any act of a similar nature considered gross misconduct' by the company's management.
Nevertheless, a tribunal could disagree with such an assessment and find in favour of a potential claimant on such grounds. Some examples are clear cut: stealing, violent aggression, criminal prosecution. Others can be tricky if an employer has been less than rigorous in monitoring or illustrating expectations and results. "
The disciplinary should have been on the grounds of potential gross misconduct, the outcome should either be gross misconduct or not. There's not a middle ground following a disciplinary.
I'd appeal anyway but if you've not got anything in writing in terms of managers asking you to do data recovery or using your own equipment it's unlikely you'll get anywhere.
Yeah they have said "potential" gross misconduct.
They have said in my final outcome its that they know I was doing it and it "could" have had serious after effects to the store, also "alleged" computer mis-use.
So in my appeal ive highlighted the fact its all here say, with could or alleged or potential..... saying its not yes or no. Goodness knows if it will count but they have no real evidence to say I did anything.
Oddly I have luckerly kept 2 pieces of paper, which is by a manager asking me to do data recoveries instore

when I was being demoted by my GM I was still running a data recovery for one of the other managers ! so when I went to collect my belongings from the technical center I snagged the 2 bits of paper along with my bag...
Sadly theres no name or managers signature on it... its just a note telling me what to do, but it is in writing and its from our own clinic manager.
I have in my appeal also got all my staff to sign a witness statement saying they see managers instructing me to do it in-store without being provided the correct tools or hdd to do the job, have no idea if that would help but its in my appeal anyhow.
After speaking to Acas employer helpline its quite clear the employer has full power regardless if a manager was in the wrong or other situation/factors took place, it all seems to be the managers can get away with it 100%.