You are meant to receive all the appeal papers approx. 10 days before the hearing. The precise wording in the current Code is as follows:
Clerks must send out appeal papers to parents, presenting officer and panel members at least 7 working days before the hearing (not including the date of the hearing or of sending out the papers).
There are two separate issues here, and Bougalou is right about both of them. First, in case the papers have got lost in the post, it would be wise for you to check with whoever is organising the appeals when the papers were posted.
Secondly, if you say at the hearing that you received the papers late and have not had sufficient time to consider the authority's case, they will inevitably adjourn the hearing to a later date.
Bougalou's clerk/panel were quite clever - they took the precaution of getting a waiver to pre-empt any possible complaint. I'm not sure most clerks/panels would think of doing this. If the hearing goes ahead with nobody raising the issue, and you are unsuccessful, you could then complain to the ombudsman about a breach of the code.
You would be asked why you hadn't raised the matter at the hearing, but most parents wouldn't have known exactly how much notice they are meant to have of the authority's case.