The accountants here were doing compilations not audits. They were relying on what Trump gave them. You can't blame the accountants when they aren't being hired to vet the information. In a compilation, the accountants aren't making any assurances on the underlying financial statements.
The only thing they have to do is if they happen to come across material errors or illegal actions, they are to report them to the client, but the assurances are the client's responsibility not the accountants. It isn't a viable defense.