[Leatherboy2006]

No legal expert here, but it seems if you filed a police report in Baltimore, they(the police) would have been able to supeona the airline for the name. Southwest was right it seems to not give you the name without a supeona. Unfortunity releasing personal information could open them up to other law suits. The subeona covers both of you and them if it goes to trail(ok to much Matlock and Perry Mason here/g/).
Since you were physically assulted you should have/had reporteded it right away. The longer you have waited the more it looks bad(I can hear Judge Judy now...screaming "and why did you wait if you were assulted...I would have been on the phone right away" you gotta love and hate her). At this point I would call Baltimore or even Detroit Police and ask their advice on how to procede legally.
Good Luck, sounds like you went through a lot