This happened to my older brother in early September, and he's finally agreed to let me post about it (he's usually embarrassed about stuff like this). He's 52, works in forestry, spends half his life in the Cairngorms, so he's not prone to flights of fancy.
He was alone checking a stand of trees about 8 miles from the nearest road when he spotted what he described as a large bipedal figure moving through dense forest about 200 metres away. Brown/dark reddish fur, hunched posture, powerful shoulders. It moved through the trees with incredible speed and purpose, and then just... vanished. No sound, which he found most unsettling. He said the scale of it didn't match any bear or deer he's ever seen.
He didn't report it officially because his employer would think he's daft. But he's worked in those forests for 30 years and he's rattled. Has anyone else had sightings in the Scottish Highlands? Are there established communities doing research up there?