Chess endgames often look deceptively simple. Reduced number of pieces on the board brings reduced alertness to the player. Thus, it is not uncommon for the adversary to come up with sneaky ways to take advantage of this relaxed state. Thinking in terms of psychology, the most important feature of this relaxed state is the reduced feeling of danger which in turn leads to reluctance to justify moves with concrete variations. Even though, schematic thinking is an important feature of endgame technique, it has a psychological danger where player's reliance upon natural moves rather than logical ones can lead h/er to trouble when there exists a non-obvious nuisance in the position which establishes a significant distinction between the natural and the logical. At the end of the day chess is purely mathematics and the term natural is nothing but pattern recognition. Yet, no pattern is exactly the same.
One form of blunder which is very common to such a frame of mind is quiescence errors where the player is decepted by the natural aesthetics of a seemingly winning move sequence and fails to spot a trap which is no further than half a move away. The main reason of the blunder is psychological, the sudden change of excitement coupled with the reduced sense of danger literally blinds the player who could otherwise easily spot the problem with the move sequence at hand. Below is a simple, illustrative example of such an error. This is an online blitz game where I had the white pieces.