SA.... I agree, I wouldn't respond or if you do, just make it a clear and concise one stating you don't know who made the calls but you suggest the kids be talked to about it. You're acknowledging it, but you're not taking responsibility for it either like he wants you to.
I recently had big spew from stbx after NC for 3 months over his inability to pay child support and it being all my fault. Oh yes! He didn't pay me child support with no fowarning, or trying to talk to me about it at all. With my attorney's help this situation was quickly resolved and I did get my child support. He then did another spewing, and now is being much nicer to me. yes I just went for a little loopdee loop on that rollercoaster... but got off a whole lot sooner this time!
Cat made a good point. WE detatch some and get away from it and then HELLO here we are again getting smacked in the face with this stuff. Very good insight, that they still must be attatched to us in order to have such strong reactions. Makes total sense, because I realize the strong feelings I still feel are a result of me still being attatched to him. But I've come so far and am so proud of myself. It will just still take time.