Disclaimers and user acceptance does not remove liability for slander, particularly against third parties.
In fact, in most EU countries "the user acknowledged" works only for a very small subset of stuff, precisely because our lawmakers know that the strong party in a contract would use that to get away from every legal obligation.
This is even worse, since the defamation in question is against a third party. This would be more like: by reading this comment, you transfer all of Bob's property to me.
In fact, in most EU countries "the user acknowledged" works only for a very small subset of stuff, precisely because our lawmakers know that the strong party in a contract would use that to get away from every legal obligation.