Taso I hear what you said. What I read is that he said we would walk if an issue like this wasn't resolved due to what their contract says. So by saying we that says to me both his wife and him would be leaving. So the client will be left with no DJ and photog that they paid for.
Now if they did do such a thing because of such a situation and someone took them to court, I wonder if their contract would stand up in court?
Also keep in mind that we're not talking a little bit of money here. He says that his price for DJ and photog is $2,700. That's not pocket change. Now ask yourself this question. If you were the client would you just let it go if they bailed on you or would you have something to say?
Personally I would let it be known on social media what they did and take them to court. I wouldn't just sweep it underneath the rug.