Do I have a case

I tool my son to the ER on Friday because he was throwing up and lethargic. ER said ear infection sent us home. Sunday he was much worse, his eye inturned and he could not focus. ER said dehydrated, gave him fluids, confirmed ear infection and said he had a stomach virus. On Monday we took him to the pediatrician because he was not acting right for a ear infection and he said he never had an ear infection or stomach virus and rushed him to the ER. We found out he had a brain tumor. Now his left eye is still inturned and it seems as if he is having a hard time seeing out of his left eye.