Recommending Other Expert Witnesses

We've had an on-going discussion with our newsletter readers about getting payment from insurance companies. Within that discussion, I received the following email with an interesting story pertinent to marketing an expert witness practice:

I provide expert witness services in the insurance and reinsurance industries both in court and in arbitrations. Here is a recent experience. I was called by "Joe", a client for whom I have been retained a few times. He needed an expert in marine cargo insurance. I declined, as this is not an area of my expertise. Joe asked if I knew of anyone who could qualify; I told him I would help if possible. I then called "Jim", a fellow expert/friend, passing along the request from Joe. Jim said he didn't qualify, but he was in turn trying to assist an attorney in locating an expert in a certain type of property insurance, and asked if I knew of anyone with that background. I said "yes-me"; Jim said he would pass it along. I then called "Dick" another expert/friend about the marine cargo. He was qualified and was grateful for the lead. I asked him to call Joe. Right after that, an attorney called, said Jim had recommended me and wanted to discuss the engagement.

Here is the outcome of these events:
-- I got the property insurance engagement from the attorney Jim was trying to help. It was a very lucrative and challenging assignment.
-- The law firm that engaged me is a major player in this arena; now they know me well, and a name partner told me "we'll work together again."
-- After testifying at the arbitration Hearing, I received calls for expert service that I traced back to recommendations from the chairman of the arbitration panel.
-- Dick was retained by Joe for the marine cargo case, and was grateful for my recommendation-this will reinforce our assisting one another in cases that we cannot take ourselves.
-- Joe called thanking me for recommending Dick-this keeps me on Joe's radar screen as well.

All of this happened as a result of me receiving a call for a case that I couldn't take. Instead of stopping at "no thanks", my thought was to help some friends and keep my name in front of them. I view every call as a possible opportunity. When approached on something outside of my expertise, I will tell the attorney "I understand that subject and have some familiarity with it. However, actual job responsibilities with the specific subject have not been sufficient to prevent me from being vulnerable under cross-examination, and I would not do anything that might detract from the merits of your case. Therefore, I must decline." Almost always, they express gratitude for expressing it as a respect for their client and the client's interest. I can then often nudge the conversation to my areas of expertise, get in a brief pitch, and follow up with a CV. Again, it's a way to create a potential opportunity out of a declination.

Sounds like a win-win situation to me. Do you see any potential pitfalls?