PIP Appeal win.

I had a F2F with ATOS in July 2018 (9 months before my Award ended)
My PIP was stopped in September - They gave me 0 0 0 0 Points
Incidentally I had hand surgery 3 days after the letter - to a hand they said was perfectly fine.
I asked for a MR and then supplied up to date Surgeons info etc
I was again turned down with 0 0 0 0 pointsin November
I got depressed about it and left it more than a month from the letter so probably could not appeal
I went to the CAB for advise and chatted to a Benefits Expert and she filled out an appeal asked me a few questions about function dressing etc. my reasons for the late appeal and sent it off.
I received confirmation from the Tribunals service (end of January) and that my appeal was late..So DWP (ATOS) had a month to contest it - they didn't obviously...
Then I had a phone call a week ago now (April), saying that my case had been reviewed and if it was acceptable they would award my points back to save me attending tribunal - no brainer.
I got my back monies that were owed today and my new award takes me past my retirement date...over 5 years
So a 9 week turnaround for the Tribunal.
My Question is, why? Why did they put me through this??? Quite Sadistic isn't it...