Some legit issues to ponder, but taking away the outlet for a fighter's passion and drive against his wishes can be as damaging as letting him fight too long. This isn't boxing; at worst Hughes will take another brutal as$-beating and walk away not sounding like a present-day Real Deal Holyfield.
Serra is just a better boxer than Hughes, IMO.
Also agree with Claudale that there are a lot of guys who, when mic'ed up, ask their corner if they got dropped or nearly choked out in the preceeding round, even in fights they ultimately win. It's even more common with fighters who actually get KO'd or choked out.