Hello, My 7year Old Son Fell Off His Scooter On

Hello,
My 7year old son fell off his scooter on Sunday at 5pm. Even though he was I great pain he walked home which wasn't too far.
I thought it was a sprain so iced it & bandaged it. My first aid isn't quiet up to date so I googke what to do all the responses suggested that his symptoms were more a broken ankle then a sprain. He was already asleep by then. He woke at 4am & I took him to emergency. They x rayed him.
They said they could see small cracks but wasn't sure if that was his normal bone or not so put him in a back slab. The cast needed changing a few days later because the swelling had gone down etc.
took him back to ED on Friday and had cast changed.
The physio who changed it said that the first cast wasn't doing anything to support him & said the x Ray report was back & he had broken his growth plate.
They put the second cast on with out x raying again. He doesn't see the fracture clinic until Wednesday sinnearly 11 days after accident.

My questions are - should I go back to ED & ask for his good ankle to be x rayed to compare with his bad foot, should I get MRI's on both feet and see a Peadiatric othopeadic doctor before leaving the ED/hospital?
My research all says this is what should happen out of 30 websites none of them differ.
I know you can only take Google searches as a guide line but when all the information is saying the same thing it's hard not to believe it more then general information or not true.

Thank you for your time