Tommy,
I don't see it happening often, but then again, I don't do it, and if an architect is secretly going behind MY back, I wouldn't necessarily know it anyway.
I did have a project manager once who had really wanted to hire Joe Lee, but was overruled by the committee. During the project, he would tell me that he had called Joe to ask his opinion. I can't fault Joe for anything. In fact, I told the Owners rep that Joe must be nicer than me, cause if he had gotten the job, and I had gotten those calls, I doubt I would give him the time of day!
I got caught in another project once, when a big remodel was awarded to another firm, but a friend I couldn't ignore, who was an influential member, asked me to visit one night. When I got there, he had the entire board assembled, and I tried to back out of it. However, I toured, and confirmed a few things that their then neophyte architecture firm probably would have figured out on their next site visit.
I have been writing a remodeling column for the new Golf Course News for six months. That has spawned almost a dozen calls to me from greens committee members asking my opinion - from up to a 1000 miles away, and without seeing the course - of how things are going at their course. In most cases, they have a competent architect and I implore them (as I did in my column) that the master plan/renovation is actually a process, not a plan, and anyone jumping in with last minute suggestions, no matter how passionate or well reasoned, is likely to do more harm than good.
Of course, I notifiy the architect in question after fielding these calls, just so he won't think I am trying to influence the project.