Is your husband sure that he understands? I don't mean that in a derogatory way, but this meetings can be stressful and difficult to follow.
It would appear this his work are saying that, on the balance of probabilities, the CCTV shows that he touched the woman, either intentionally or accidentally.
It would appear that whatever the contact was is so inappropriate that it is a dismissal offence.
It also appears that while the woman made a different allegation, which cannot be backed up by the CCTV, the contact that they can see is enough for them to terminate his employment.
He can appeal, but he'll need to make sure that he understands. If the CCTV does show him touch her, and he appeals saying that he didn't, it won't stand. Does he have any excuse for being so close to the woman that he could accidentally touch her where he did?
Who was his companion? A union member or a friend?
It might be worth checking to see if your home insurance has legal cover, and if it does, if this is covered.