Being sued

My fiancee is an insurance broker. He is being threatened to be sued, along with the insurance company, the private adjuster, the contractor, and everyone else remotely involved, for problems related to a claim. My fiancee honestly doesn't believe he has done anything wrong but it looks like he will be forced to pay to defend himself. He carries an errors and omissions policy but it has a $5000 deductible which we would like to not have to pay. My question is threefold -- Is there anything he can say to his client to encourage/force him to drop the lawsuit? If he is named in the lawsuit, should he defend himself? And if he is not found to be guilty, is there any way he can recover from the plaintiff the legal fees he may to forced to pay?

In answer:

Q1) "Is there anything he can say to his client to encourage/force him to drop the lawsuit?"
A1) Depends entirely on the circumstances of the lawsuit. If the Plaintiff feels that your Fiance is at fault or liable, then probably not. If your Fiance is at true 'arms length', then maybe... but, he may have to do a LOT of convincing and threat to take counter-action for false and malicious prosecution, etc. Finally, if the Plaintiff has any case at all that includes him, he could certainly arrange an out of court settlement. After all, that is what a lot of suits are about anyway.

Q2) "If he is named in the lawsuit, should he defend himself?"
A2) Absolutely!!! Either he needs to defend himself or he will become the scapegoat for all the other defendants to dump their cases on.

Q3) "And if he is not found to be guilty, is there any way he can recover from the plaintiff the legal fees he may to forced to pay?"
A3) Depends. If the lawsuit is totally frivolous and without merit, and depending on the claims being made, his legal expenses MIGHT be compensable. Only his attorney can decide that based on the facts.