A trap to be aware of: when you talk to teachers about what your child can do, and you're drawing on what you've seen your child do in such a supported setting, it's easy to give a misleading impression. Even if you aren't actually called on to offer much real help, the mere fact of help being available, IME, can let your child tackle things that would seem insurmountable without it. If things you have said they can do then do seem insurmountable to them when the teacher asks them to do them independently, you may have a problem... I'm currently hoping that I've offered a suitable mix of detail and vagueness to have avoided giving DS's current teacher such a misleading impression!
have gone around this bend with the school;
If a child's able to do something with a little support at home, he should be given similar opportunities and support in the classroom, but apparently that is asking too much.