Suppose Larry the landlord applied to court for possession order and presents a back dated copy of section 21 notice from 65 days ago.
The court serves notice of hearing to the property and tenant attends claiming it is the first they've seen of the landlord wanting the property back and there was never any such notice served. What does the court do? Accept or reject that valid notice was served?
Conversely, what stops a tenant from quietly discarding notices received and then in court denying receiving them?