There is probably a Memory Leak on the field ServerModel.filterModels (a collection of FilterModel).
As a FilterModel reference the service/bundle of a filter, when a bundle is refreshed/updated, the classloader can't be garbage collected.
The methode ServerModel.removeFilterModel checks only the filterClass on the filterModel. If the filterClass is not set, then the FilterModel is not found and not removed.
However, when a Filter is registered throught the whiteboard extender, it doesn't fill the filterClass field :
FilterWebElement.register() call webContainer.registerFilter(<filter>) without the class
HttpServiceStarted.registerFilter call the constructor FilterModel() without a filterClass