Efficient client intake is a difficult process. Many clients turn out to be great clients, but some turn out to be more trouble than they are worth. When another lawyer comes looking for advice or representation, how do you decide?
Do you know the person?
If the person is a family friend, or a friend, the alarms have sounded. Not only are you representing another lawyer, but you are mixing business with your personal life.
If something goes wrong, your personal relationship can be damaged. You will also likely be subjected to intense second-guessing by your friend, perhaps more so than if this was just a friend, not a friend who is also a lawyer.
What are they like as an attorney?
If you know them as a friendly, cooperative, and generally easy to deal with lawyer, that is at least a step in the right direction. If they are regarded as a nasty litigator, say no thanks.
Being a client and practicing law are two different things, but how they relate to other people is unlikely to experience a significant shift.
Draw the line
If they pass the first two tests, and you are willing to consider their case, draw the line. You are the attorney, they are the client. You call the shots on strategy and they need to agree to that up front.
Whatever type of law you practice, you practice it because you are good at it. Having someone arm-chair quarterback your case can only lead to bad things. No matter what you say, you are bound to experience some second-guessing. But if you draw the line up front, you can hopefully set the right the precedent, and minimize having a backseat driver as a client.