HSMP Entry Clearance Appeal

My husband got his HSMP approval from home office in London but then had to go to India in order to apply for HSMP Entry Clearance.
At his interview for Entry Clearance in India, he was rejected the entry clearance because they think that he obtained HSMP by deception. Now, the reason behind this was just an unanswered call. The Home office employee tried ringing my husband's employer in India and because there was no answer over the phone, HO employee concluded that the company does not exists and he obtained HSMP by deception purely based on an unanswered phone call.
I have spoken to a lawyer in UK who are OISC affiliated and they think our case is quite strong and lawyer will file an appeal in the coming week.

Could someone please tell me how long does it take before we find out if home office has accepted the appeal or not? Also, I have heard that in some appeals they give visa but in some cases they don't and the appeal goes to the court.
In this appeal do you know what are the chances of him getting visa without going to the court?