since then he has kept quiet and converted as much asset as possible to about 850 bitcoins.
he just sprung the divorce on his ex-wife and now her lawyer is arguing he must have much more money than he claims to be.
the judge ordered he must turn over all his assets to give one half to his ex-wife.
does the court have right of access to his bitcoin wallet?
It would not be possible to seize BTC that your former roommate has in his wallet.
With that being said in the event that a Judge finds that he did in fact hide assets (or not comply with an order to give assets to his former wife) then he could be held in contempt of court (put in jail) until he complies.
Personally I would not risk my freedom for a few hundred thousand dollars (or even millions of dollars).