A plausible reason would be that he was not looking to have an affair but rather was actively seduced. Someone not looking to have an affair would not use a matchmaking service.

Remember that in the above scenario the seducer is an agent for hire (or she's doing it for patriotic or other reasons), not genuinely in love with the rich exec. Honest matchmaking can't guarantee the same experience in every instance.

Obviously the exec could have paid for the same service himself, but that wouldn't be called matchmaking (and it's not what most people seek).

They don't go out and find your perfect match, they get someone that works for them to act like your perfect match.

This does exist as a service and is considered by many to be the oldest profession in the world.