I despair, as a Catholic. I am sure that Fr. Lombardi is a nice, well meaning man, but it seems that his efforts at outreach went over like a ...well they don't seem to be well received. I suspect it is very hard for a priest who is used to being in a position of authority to find himself in a position of humility and to know what to do. And yet this kind of humility is central to the teachings of Jesus. There are so many stories of Jesus showing compassion to those rejected by everyone else in society. I'd advise Fr. Lombardi to try to reach out as Jesus might -- with absolute compassion. without preconditions. I have some specific advice on what he could say and do instead of what he did say and do.
My first bit of advice is don't try to control the setting to where you are comfortable. Try to make sure that the survivors are in a comfortable setting. Ask the survivors where they want to meet with you and how many want to meet with you. Try to accommodate as much as you can. It is hard to be confronted with shouts and criticism. You can do it. See it as a challenge to grow in spirituality, rather than as a problem to be managed or controlled.
Below is Fr. Lombardi's letter in white. My advice in red and my rewritten letter in blue.