Once an auto insurance claim is denied, can it be reopened and/or accepted?

I had an auto accident and after interviewing me and looking at my photos taken right after the accident, my insurance company believed that I was not at-fault and denied the other driver's claim and closed the case. He then claimed he had photos that would prove that I was the one at fault and would mail it to them. If he can somehow prove it, is it possible my insurance company will change their mind and reopen the case? Or once it's closed, it's final?