Two men were candidates for an important post. A third man introduced them both to an audience of professionals. His introduction was able and fair. The ensuing debate went well for both sides.
A couple of weeks later, the master of ceremonies endorsed one of the candidates. The other candidate grumbled that he was baffled by the endorsement of his rival because he knew that his positions were so much closer to those favored by the emcee. He ascribed the third man's actions either to opportunism (his rival was ahead in the polls) or ignorance.
The real reason, however, was far simpler. After the debate, his rival had crossed the room to thank the master of ceremonies and to ask for his opinion on an issue. The other man had not.
His "logic" had failed to include the human factor.