What can a defendant argue when faced with an application for costs due to a Calderbank offer?

In the context of a Calderbank offer, the defendant can reasonably argue that the applicant was not able to meet the terms of the offer. A Calderbank offer is a type of settlement offer that is made "without prejudice save as to costs," meaning it can be presented to the court when determining costs if the offer is not accepted and the case proceeds to a final hearing.

If the defendant can demonstrate that the applicant was unable to fulfill the conditions outlined in the Calderbank offer, this could potentially influence the decision regarding costs. Courts often look at whether the party making the offer had a genuine approach to settlement and whether the other party could realistically abide by the proposal. Therefore, being unable to meet the terms of the offer can play a significant role in the court's considerations around costs awarding.

The other options focus on various factors that may not directly address the implications of the Calderbank offer in relation to costs. The unfairness of the offer or procedural flaws in the application do not generally negate the potential impact of the offered settlement in the context of costs. Additionally, arguing that the Calderbank offer was irrelevant to the dispute does not align with the purpose of such offers, which is to facilitate settlement discussions.