Some kids are just extra happy to be with mum. My DS1 still cried all through the first 3 terms of kindergarten. My DS4 is 3.5 now and hates going. He screams and cries and hides under the table so he doesn't have to go. Then has a great day when he actually gets there. I would definitely meet with the carer when you have your questions ready and are more able to concentrate. If its just the separation anxiety I wouldn't hesitate in booking him for 4 year old kindy next year and like someone else said - if it's still an issue later he can do 4 year old kindy twice.