Burden of knowledge
The burden of knowledge is an often-invoked excuse for why a player did not correctly answer a tossup in a subject area s/he is well-known for liking and/or being good at. Generally speaking, the burden of knowledge arises when a player believes that a clue applies to two or more possible answers, leading that player to wait for a clue to disambiguate the answers, while another player who only knows the clue in connection with one possible answer immediately buzzes and is correct.
A variant of the burden of knowledge (perhaps the burden of meta-knowledge) occurs when a player discounts the correct answer in the belief that a clue could possibly apply to other answers of which s/he knows nothing, or that an early clue well-associated with one answer would be later in the question if the clue were actually pointing to that answer. This is especially prominent at tournaments that have wild difficulty swings and/or poor questions and is often seen in games of buzzer chicken.