I recently changed the way i recognize repetition of position draws within the search. The search starts with the actual game history and any time a position is repeated a draw score is immediately returned. In the following position:
5rk1/p2R1p1p/1p2p1pQ/1P6/P3q1P1/7P/2r3P1/5R1K w - - 0 1
It finds the drawing move 1. h6xf8+ but after the sequence of moves 1...g8xf8, 2. f1xf7+ f8-e8, 3. f7-e7+ e8-f8, 4. e7-f7+ f8-g8, 5. f7-g7+ g8-f8
now it sees that playing 6. g7-e7 repeats a previous position and thinks its a draw. Instead its not check and he's let black of the hook. Black then wins easily.
I suppose if i generated checks before the other quiet moves this may not have happened. But thats not what i currently do. Is this just a rare case thats the cost of being able to see these repetitions quickly in the search or is there something else people do to avoid this situation. It does;t seem that rare.