Yes, it would be really amazing if it had never happened. Since "reports" are only required in the case of accidents, here are extracts from three NTSB summaries:
WPR13CA155
During descent for an off-airport pinnacle landing, the helicopter
encountered a downdraft about 75 to 100 feet above ground level (agl),
and the pilot receiving instruction increased collective input. The
flight instructor advised the pilot receiving instruction to be less
aggressive using the collective as the flight continued to the landing
area. As the helicopter descended through about 10 to 25 feet agl, it
encountered a second downdraft, and the pilot receiving instruction
increased collective again, which was followed by a decrease in rotor
rpm.
ANC09LA098
During the approach to the 5,657 foot level site, the pilot said he
encountered a downdraft as the helicopter approached the site, and the
helicopter descended below his anticipated approach path. He initiated
a go-around, but the helicopter continued to descend, and landed hard,
about 150 feet short and down slope of his intended touchdown point.
WPR09CA470
As he flew the helicopter out of the leeward side of the peak, he
encountered a downdraft. He maneuvered the helicopter toward a wide
open valley that descended about 5,000 feet below. The downdraft
pushed the helicopter into the face of the mountain, despite the
pilot's application of full collective and descending flight into the
valley.