You never really know what the course of communication was when the contract was negotitated and signed or when Brown made the decision to stay at home and not attend the off season workouts.
Did he even call or write the agent Overstreet and tell him that he wanted an answer on that decision before he made it?
I doubt there is going to be any lawsuit because there probably are some letters or e-mails from when the contract was signed specifically explaining the bonuses and Brown probably did not even call or write the agent to ask about his decision not to attend workouts.
From Googling his name, looks like Overstreet has a lot of name players and maybe they are satisfied with his representation.
If Brown did not know that 2/3 of his salary depended on 1 bonus, I would not assume that he never got that specific information in a separate writing from the signed contract. Of course, the signed player contract has too many pages, but more than likely he got that inforamtion in a one page summary or e-mail.
Where Ignorance is Bliss, 'Tis Folly to be Wise.