Do you think the web pages I read were made by people with less authority than a tweet from a random lawyer?
To give him his due - he isn't just a random lawyer but a rather senior one - indeed a Faculty Dean. But actually it is then kind of becomes his professional job to warn people to be careful in what they post. Fair enough but we what we are talking about his isn't the
bluntness of the law - in other word what might, in theory, result in a contempt prosecution, but the
precision of the law - in other words what comments would be sufficient to vault the threshold of likelihood to result in a serious interference with the administration of justice and that a prosecution would be in the public interest - noting that it is in the public interest to allow free speech.
As I've said previously the McLaughlin situation seems certain to clarify where the law sits in practice - on the basis of whether there is a decision to prosecute and also if that is the case whether that prosecution is successful.