My understanding of Pan F based on what others here have said is that, once exposed, the latent image on the film doesn't last as long as on other films so once you expose it then process the film as soon as possible. However I have seen nothing that suggests an unexposed Pan F doesn't have the same longevity as other films.

If it did then retailers would presumably be advised to sell the film within a relatively short time and I have heard nothing that suggests that Ilford gives that advice to its retailers in comparison with its other films