I am inclined to agree with Rayvn.
I haven't experienced this yet persay--but I did experience a jw baby shower I was explicitly NOT invited to. (Death/birth different but equal yes no?) Anyway I sent the card (with my phone number and a request that they call me when they needed a babysitter) and a gift. Did I get anythiing back? Nope. Was I expecting to? I dunno, I did expect at least a thank you card, but I guess not. Does it hurt. Hell yes. (especially since I am not df or da.) But did I do the right thing. I think I did. Regardless of how they feel about me, my feelings for them have not changed one bit. I think it's important they be reminded of that during big life-altering events like this.
I remember so many times as a kid, or while I was still in talking about DF and DA people like they didn't care, and how could they be so cold to turn their backs on us? When all we did was love them! (I know laughable now) but I did take their silence to mean they stopped caring and wanted nothing to do with us simply because of how we believed.
Now being on the otherside, I don't want them to ever think I stopped carring about them simply because of what they believe. I don't agree with what they believe, and find what they believe to be harmful and dangerous...but I will never hate THEM because of it. Nor will I stop caring for them.
Therefore, while I have never experienced a funeral situation like this, I know already how I would react. They would get a card with my deepest sympathy and respect, and a promise to be there for them should they ever feel the need to talk.
I am still here. If they want me they can find me. I want it to always be PERFECTLY OBVIOUS who cut out who. If they want to play petty games so be it. I will not.