HaltedTraverserStrategy should recurse into collections for detachment.

public static <D> D detach(final Object object) {
        if (object instanceof Element) {
            return (D) ReferenceFactory.detach((Element) object);
        } else if (object instanceof Property) {
            return (D) ReferenceFactory.detach((Property) object);
        } else if (object instanceof Path) {
            return (D) ReferenceFactory.detach((Path) object);
        } else if (object instanceof List) {
            final List list = new ArrayList();
            for (final Object item : (List) object) {
                list.add(ReferenceFactory.detach(item));
            }
            return (D) list;
        } else if (object instanceof Set) {
            final Set set = object instanceof LinkedHashSet ? new LinkedHashSet() : new HashSet();
            for (final Object item : (Set) object) {
                set.add(ReferenceFactory.detach(item));
            }
            return (D) set;
        } else if (object instanceof Map) {
            final Map map = object instanceof LinkedHashMap ? new LinkedHashMap() : new HashMap();
            for (final Map.Entry<Object, Object> entry : ((Map<Object, Object>) object).entrySet()) {
                map.put(ReferenceFactory.detach(entry.getKey()), ReferenceFactory.detach(entry.getValue()));
            }
            return (D) map;
        } else {
            return (D) object;
        }
    }