Yes, they have missed the deadline. However, don't get into a game of WS ping-pong. When the judge issues the orders after reviewing your request, you will know when and where the hearing is going to take place.
At the hearing you can point out to the judge that the claimants supplementary WS was issued late and is made by a paralegal in the employ of the claimants solicitor and not someone with firsthand knowledge and is should be dismissed.
The judge will not be happy with their messing about. All judges want is a a quiet life. The judge hearing the case will only have seen the bundle maybe 5 or 10 minutes before the hearing. They will not have time to read anything in depth.
They will have a look at the PoC, the defence and then skim the WS for the facts, if they're obvious. The question is, has the claim been made properly? Has the claim been defended properly? Is the claim valid? Has the defendant rebutted the claim properly? Decision will be made after maybe a few questions and that will be it.
In this case, you have to make it clear at the start that the claimants WS is not a true WS as the "witness" is not even employed by the claimant and is not there to be cross examined. There is no cause of action against you as the Keeper because the Notice to Keeper is nt compliant with PoFA 9(2)(a) as there is no period of parking noted, just a single observed time. The persuasive appellate case of Brennan v Premier Parking Solutions makes it clear that a single observation time is not sufficient to satisfy PoFA 9(2)(a).
Additionally, for a contract to be formed, there must be a consideration period. None has been evidenced and therefore there is no evidence of a contract having been formed with the driver.
Those are your main points of defence.