Thanks for the support. I left work and went to the daycare to talk to the teacher. She hit the teacher on the leg and when she started to document her actions for me she took the paper out of her hands and threw it in the trash. The director told me that difficult child 'ripped the paper out of her hands and tore it into little pieces'. That was the behavior that was weird to me. The rest was bad, yelling and saying "no", but I found the trigger, at least.
difficult child was laying quietly on her cot (big feat for her) when her teacher came over to praise her and rub her back. Another student, one with special needs (does not speak at age 4) starting screeching and running aroudn the room. She left difficult child to get the student under control and then she got up and mimicked the other child's behavior, I'm sure to get the attention that he took away from her. The teacher didn't realize what she'd done to difficult child by leaving her to tend to the behavior problem. It told her that running around=more attention.
So we spoke to the director, both husband and I, and they said that if it happens again she will be terminated. Period. I told her about the psychologist and the early intervention evaluations, and she said that she'd consider it. I"m talking to my boss tomrorrow aobut taking a leave of absence from work.