Entity Hider Class cancels Knockback

I have a problem with this protocol lib code I use to make an entity toggle visibility.

Code:

    /**
     * Allow the observer to see an entity that was previously hidden.
     * @param observer - the observer.
     * @param entity - the entity to show.
     * @return TRUE if the entity was hidden before, FALSE otherwise.
     */
    public final boolean showEntity(Player observer, Entity entity) {
        validate(observer, entity);
        boolean hiddenBefore = !setVisibility(observer, entity.getEntityId(), true);

        // Resend packets
        if (manager != null && hiddenBefore) {
            manager.updateEntity(entity, Arrays.asList(observer));
        }
        return hiddenBefore;
    }

    /**
     * Prevent the observer from seeing a given entity.
     * @param observer - the player observer.
     * @param entity - the entity to hide.
     * @return TRUE if the entity was previously visible, FALSE otherwise.
     */
    public final boolean hideEntity(Player observer, Entity entity) {
        validate(observer, entity);
        boolean visibleBefore = setVisibility(observer, entity.getEntityId(), false);

        if (visibleBefore) {
            PacketContainer destroyEntity = new PacketContainer(ENTITY_DESTROY);
            destroyEntity.getIntegerArrays().write(0, new int[] { entity.getEntityId() });

            // Make the entity disappear
            try {
                manager.sendServerPacket(observer, destroyEntity);
            } catch (InvocationTargetException e) {
                throw new RuntimeException("Cannot send server packet.", e);
            }
        }
        return visibleBefore;
    }

The issue is when a player is made visible they sometimes sink into the floor and they do not take any knock back. I am running this code on a 1.7.10 server, I think that maybe the bug is Minecraft related.

 

Hmm, all you want to do here is make a player vanish? Why not using the API?
Also there is a method in the NMS class Entity (I belive, unless it's a subclass) called "setVisible(Boolean param)" which acts like adding invisibility potion to the player without particles. That may work.

I don't really know why this code makes the player glitch in such a way though, can't help on that