Java EE SDK :: CDI Bean Cannot Access Public Method Of Unmodifiable Collection

I've got a CDI bean which is a facade for a JPA entity. Such entity has got a many to one relationship with itself and I've got the following method:

public Set<Account> getChildren() {
        return this.children;
}

which is called in a JSF/Facelets page:

<h:commandLink action="#{accountController.destroy}" value="#{bundle.ListAccountDestroyLink}" rendered="#{item.children.size() == 0}"/>I then decided to return an unmodifiable set and changed getChildren() accordingly:
public Set<Account> getChildren() {
        return Collections.unmodifiableSet(children);
}

The page now reports this error:

java.lang.IllegalAccessException: Class javax.el.BeanELResolver can not access a member of class java.util.Collections$UnmodifiableCollection with modifiers "public"
     at sun.reflect.Reflection.ensureMemberAccess(Reflection.java:65)
     at java.lang.reflect.Method.invoke(Method.java:588)

[Code] ....

javax.el.BeanELResolver is incorrectly failing because it's trying to invoke the size() method using reflection without correctly taking into account the method visibility (which is indeed invokable programmatically). I'm running NetBeans 6.8, Glassfish 3.0 and jdk1.6.0_17.

Is this a bug in BeanELResolver?