By Charter [webmasterworld.com] we don't permit threads with specific legal issues to be posted here. Although you have changed the (domain)names to protect the innocent it still asks for fairly specific legal guidance.
A large component of the problem with legal opinion threads is that a valid legal opinion requires a great deal of information, including detailed facts and a depth of knowledge of the law of the jurisdictions that may decide the issue. We don't allow mention of specific domain names and you wouldn't want to do that anyway as any statements you make here might be used against you in a judicial proceeding.
Sorry, but I don't think we'll be able to offer much help with your issue.
Company A who has applied first forgets to send the required information via postal mail and hence the application is expired. Company B sends the information and is granted the domain.
Does company A have a priority in getting the domain in regards to the fact that they own the trademark to the full domain as oppose to company B who owes part of the trademark?
If you think about it, why should Company A be given priority when they had the chance to meet all the requirements, failed to do so, then the name was granted to Company B? It's not simply a matter of who's first, but who completes the requirements first. ;)