Just a quick note to say hi! I am a parent of a child with special needs, and a special education teacher. My advice... tell them that the IEP is out of compliance. You need four people to be there and sign to make up the IEP "team".
If you do not want to do that go back and ask for another meeting to addend the IEP, and explain that you had no input and decisions were made without you... IEP= You hold all the power!