They weren't protecting him - they were protecting themselves from huge lawsuits! You can't libel the dead but you can certainly libel the living. JS was still alive and as this is an anonymous forum so where was the proof? JS couldn't sue every poster (without a load of hassle anyway) but he could have certainly sued DS. If JS had got nasty the whole of DS could have been shut down (worse case scenario of course but it could still have cost them a lot of money.) DS were (are) responsible for what is written on their forum, therefore anything considered libellous got closed down.
Now he's dead they can leave the threads/posts there for all to see.
If what you're saying is true, then they can't sue you (successfully) for libel. Apparantly, people did have proof, so they could have taken him down when he was alive.