Depression and any other excuse is going to be a shot in the dark. I have been on 1 committee where the person was bi-polar and no one cared.
What I have noticed in all the committees I was on in which someone avoided DE'ing they ALWAYS spoke about how hurt they are that Jehovah and his name were scarred by their actions. If something to that effect is not mentioned then it is assumed that the person only cares for themselves.
I would get out my shepherding book and show you that it basically states if a person shows true repentance then spare them. Point. Blank. Period.
Show as many "sincere" forms of repentence as possible. But as Istated before a very powerful line that I noticed stuck with me was where it speaks about how "true repentence many not be displayed up until their actions are put before them in the committee".
You can try legal action... it maaaay work. It may not.
You can try denying everything... that maaay work but if there is any proof at all you are screwed.
However if you demonstrate repentence and they still df you - which is against there own rules, and you appear before an appeal committee then you have a better chance..
Just my Opinion
P.S. - Also keep in mind threatening legal issues although if it saves you from a DF will still have you in a situation just as bad if not worse then if you were df'ed
Acting like you are depressed etc... will also cause you issues as well because it will get around that you have issues. Which maaay not be so bad so this is a viable option but I would not use it alone.